diff --git a/boot.php b/boot.php
index a4d0fe5c73..d291220ce8 100644
--- a/boot.php
+++ b/boot.php
@@ -27,14 +27,7 @@
  * easily as email does today.
  */
 
-use Friendica\Core\Protocol;
-use Friendica\Core\System;
-use Friendica\Database\DBA;
-use Friendica\DI;
 use Friendica\Model\Contact;
-use Friendica\Model\Notification;
-use Friendica\Util\BasePath;
-use Friendica\Util\DateTimeFormat;
 
 define('FRIENDICA_PLATFORM',     'Friendica');
 define('FRIENDICA_CODENAME',     'Siberian Iris');
@@ -51,51 +44,6 @@ define('NEW_TABLE_STRUCTURE_VERSION', 1288);
  */
 define('EOL',                    "<br />\r\n");
 
-/**
- * Image storage quality.
- *
- * Lower numbers save space at cost of image detail.
- * For ease of upgrade, please do not change here. Set system.jpegquality = n in config/local.config.php,
- * where n is between 1 and 100, and with very poor results below about 50
- */
-define('JPEG_QUALITY',            100);
-
-/**
- * system.png_quality = n where is between 0 (uncompressed) to 9
- */
-define('PNG_QUALITY',             8);
-
-/**
- * An alternate way of limiting picture upload sizes. Specify the maximum pixel
- * length that pictures are allowed to be (for non-square pictures, it will apply
- * to the longest side). Pictures longer than this length will be resized to be
- * this length (on the longest side, the other side will be scaled appropriately).
- * Modify this value using
- *
- * 'system' => [
- *      'max_image_length' => 'n',
- *      ...
- * ],
- *
- * in config/local.config.php
- *
- * If you don't want to set a maximum length, set to -1. The default value is
- * defined by 'MAX_IMAGE_LENGTH' below.
- */
-define('MAX_IMAGE_LENGTH',        -1);
-
-/**
- * Not yet used
- */
-define('DEFAULT_DB_ENGINE',  'InnoDB');
-
-/** @deprecated since version 2019.03, please use \Friendica\Module\Register::CLOSED instead */
-define('REGISTER_CLOSED',        \Friendica\Module\Register::CLOSED);
-/** @deprecated since version 2019.03, please use \Friendica\Module\Register::APPROVE instead */
-define('REGISTER_APPROVE',       \Friendica\Module\Register::APPROVE);
-/** @deprecated since version 2019.03, please use \Friendica\Module\Register::OPEN instead */
-define('REGISTER_OPEN',          \Friendica\Module\Register::OPEN);
-
 /**
  * @name CP
  *
@@ -111,72 +59,6 @@ define('CP_USERS_AND_GLOBAL',       2);
  * @}
  */
 
-/**
- * These numbers are used in stored permissions
- * and existing allocations MUST NEVER BE CHANGED
- * OR RE-ASSIGNED! You may only add to them.
- */
-$netgroup_ids = [
-	Protocol::DFRN     => (-1),
-	Protocol::ZOT      => (-2),
-	Protocol::OSTATUS  => (-3),
-	Protocol::FEED     => (-4),
-	Protocol::DIASPORA => (-5),
-	Protocol::MAIL     => (-6),
-	Protocol::FACEBOOK => (-8),
-	Protocol::LINKEDIN => (-9),
-	Protocol::XMPP     => (-10),
-	Protocol::MYSPACE  => (-11),
-	Protocol::GPLUS    => (-12),
-	Protocol::PUMPIO   => (-13),
-	Protocol::TWITTER  => (-14),
-	Protocol::DIASPORA2 => (-15),
-	Protocol::STATUSNET => (-16),
-	Protocol::NEWS      => (-18),
-	Protocol::ICALENDAR => (-19),
-	Protocol::PNUT      => (-20),
-
-	Protocol::PHANTOM  => (-127),
-];
-
-/**
- * Maximum number of "people who like (or don't like) this"  that we will list by name
- */
-define('MAX_LIKERS',    75);
-
-/**
- * @name Notification
- *
- * Email notification options
- * @{
- */
-/** @deprecated since 2020.03, use Notification\Type::INTRO instead */
-define('NOTIFY_INTRO',        Notification\Type::INTRO);
-/** @deprecated since 2020.03, use Notification\Type::CONFIRM instead */
-define('NOTIFY_CONFIRM',      Notification\Type::CONFIRM);
-/** @deprecated since 2020.03, use Notification\Type::WALL instead */
-define('NOTIFY_WALL',         Notification\Type::WALL);
-/** @deprecated since 2020.03, use Notification\Type::COMMENT instead */
-define('NOTIFY_COMMENT',      Notification\Type::COMMENT);
-/** @deprecated since 2020.03, use Notification\Type::MAIL instead */
-define('NOTIFY_MAIL',        Notification\Type::MAIL);
-/** @deprecated since 2020.03, use Notification\Type::SUGGEST instead */
-define('NOTIFY_SUGGEST',     Notification\Type::SUGGEST);
-/** @deprecated since 2020.03, use Notification\Type::PROFILE instead */
-define('NOTIFY_PROFILE',     Notification\Type::PROFILE);
-/** @deprecated since 2020.03, use Notification\Type::TAG_SELF instead */
-define('NOTIFY_TAGSELF',     Notification\Type::TAG_SELF);
-/** @deprecated since 2020.03, use Notification\Type::TAG_SHARE instead */
-define('NOTIFY_TAGSHARE',    Notification\Type::TAG_SHARE);
-/** @deprecated since 2020.03, use Notification\Type::POKE instead */
-define('NOTIFY_POKE',        Notification\Type::POKE);
-/** @deprecated since 2020.03, use Notification\Type::SHARE instead */
-define('NOTIFY_SHARE',       Notification\Type::SHARE);
-
-/** @deprecated since 2020.12, use Notification\Type::SYSTEM instead */
-define('NOTIFY_SYSTEM',      Notification\Type::SYSTEM);
-/* @}*/
-
 /**
  * @name Gravity
  *
@@ -204,18 +86,6 @@ define('PRIORITY_NEGLIGIBLE', 50);
 define('PRIORITIES', [PRIORITY_CRITICAL, PRIORITY_HIGH, PRIORITY_MEDIUM, PRIORITY_LOW, PRIORITY_NEGLIGIBLE]);
 /* @}*/
 
-/**
- * @name Social Relay settings
- *
- * See here: https://github.com/jaywink/social-relay
- * and here: https://wiki.diasporafoundation.org/Relay_servers_for_public_posts
- * @{
- */
-define('SR_SCOPE_NONE', '');
-define('SR_SCOPE_ALL',  'all');
-define('SR_SCOPE_TAGS', 'tags');
-/* @}*/
-
 // Normally this constant is defined - but not if "pcntl" isn't installed
 if (!defined("SIGTERM")) {
 	define("SIGTERM", 15);
@@ -229,6 +99,14 @@ if (!defined('CURLE_OPERATION_TIMEDOUT')) {
 	define('CURLE_OPERATION_TIMEDOUT', CURLE_OPERATION_TIMEOUTED);
 }
 
+if (!function_exists('exif_imagetype')) {
+	function exif_imagetype($file)
+	{
+		$size = getimagesize($file);
+		return $size[2];
+	}
+}
+
 /**
  * Returns the user id of locally logged in user or false.
  *
@@ -323,200 +201,3 @@ function info($s)
 
 	$_SESSION['sysmsg_info'][] = $s;
 }
-
-function feed_birthday($uid, $tz)
-{
-	/**
-	 * Determine the next birthday, but only if the birthday is published
-	 * in the default profile. We _could_ also look for a private profile that the
-	 * recipient can see, but somebody could get mad at us if they start getting
-	 * public birthday greetings when they haven't made this info public.
-	 *
-	 * Assuming we are able to publish this info, we are then going to convert
-	 * the start time from the owner's timezone to UTC.
-	 *
-	 * This will potentially solve the problem found with some social networks
-	 * where birthdays are converted to the viewer's timezone and salutations from
-	 * elsewhere in the world show up on the wrong day. We will convert it to the
-	 * viewer's timezone also, but first we are going to convert it from the birthday
-	 * person's timezone to GMT - so the viewer may find the birthday starting at
-	 * 6:00PM the day before, but that will correspond to midnight to the birthday person.
-	 */
-	$birthday = '';
-
-	if (!strlen($tz)) {
-		$tz = 'UTC';
-	}
-
-	$profile = DBA::selectFirst('profile', ['dob'], ['uid' => $uid]);
-	if (DBA::isResult($profile)) {
-		$tmp_dob = substr($profile['dob'], 5);
-		if (intval($tmp_dob)) {
-			$y = DateTimeFormat::timezoneNow($tz, 'Y');
-			$bd = $y . '-' . $tmp_dob . ' 00:00';
-			$t_dob = strtotime($bd);
-			$now = strtotime(DateTimeFormat::timezoneNow($tz));
-			if ($t_dob < $now) {
-				$bd = $y + 1 . '-' . $tmp_dob . ' 00:00';
-			}
-			$birthday = DateTimeFormat::convert($bd, 'UTC', $tz, DateTimeFormat::ATOM);
-		}
-	}
-
-	return $birthday;
-}
-
-/**
- * Check if current user has admin role.
- *
- * @return bool true if user is an admin
- */
-function is_site_admin()
-{
-	$a = DI::app();
-
-	$admin_email = DI::config()->get('config', 'admin_email');
-
-	$adminlist = explode(',', str_replace(' ', '', $admin_email));
-
-	return local_user() && $admin_email && DBA::exists('user', ['uid' => $a->getLoggedInUserId(), 'email' => $adminlist]);
-}
-
-/**
- * Returns the complete URL of the current page, e.g.: http(s)://something.com/network
- *
- * Taken from http://webcheatsheet.com/php/get_current_page_url.php
- */
-function curPageURL()
-{
-	$pageURL = 'http';
-	if (!empty($_SERVER["HTTPS"]) && ($_SERVER["HTTPS"] == "on")) {
-		$pageURL .= "s";
-	}
-
-	$pageURL .= "://";
-
-	if ($_SERVER["SERVER_PORT"] != "80" && $_SERVER["SERVER_PORT"] != "443") {
-		$pageURL .= $_SERVER["SERVER_NAME"] . ":" . $_SERVER["SERVER_PORT"] . $_SERVER["REQUEST_URI"];
-	} else {
-		$pageURL .= $_SERVER["SERVER_NAME"] . $_SERVER["REQUEST_URI"];
-	}
-	return $pageURL;
-}
-
-function get_temppath()
-{
-	$temppath = DI::config()->get("system", "temppath");
-
-	if (($temppath != "") && System::isDirectoryUsable($temppath)) {
-		// We have a temp path and it is usable
-		return BasePath::getRealPath($temppath);
-	}
-
-	// We don't have a working preconfigured temp path, so we take the system path.
-	$temppath = sys_get_temp_dir();
-
-	// Check if it is usable
-	if (($temppath != "") && System::isDirectoryUsable($temppath)) {
-		// Always store the real path, not the path through symlinks
-		$temppath = BasePath::getRealPath($temppath);
-
-		// To avoid any interferences with other systems we create our own directory
-		$new_temppath = $temppath . "/" . DI::baseUrl()->getHostname();
-		if (!is_dir($new_temppath)) {
-			/// @TODO There is a mkdir()+chmod() upwards, maybe generalize this (+ configurable) into a function/method?
-			mkdir($new_temppath);
-		}
-
-		if (System::isDirectoryUsable($new_temppath)) {
-			// The new path is usable, we are happy
-			DI::config()->set("system", "temppath", $new_temppath);
-			return $new_temppath;
-		} else {
-			// We can't create a subdirectory, strange.
-			// But the directory seems to work, so we use it but don't store it.
-			return $temppath;
-		}
-	}
-
-	// Reaching this point means that the operating system is configured badly.
-	return '';
-}
-
-/**
- * Returns the path where spool files are stored
- *
- * @return string Spool path
- */
-function get_spoolpath()
-{
-	$spoolpath = DI::config()->get('system', 'spoolpath');
-	if (($spoolpath != "") && System::isDirectoryUsable($spoolpath)) {
-		// We have a spool path and it is usable
-		return $spoolpath;
-	}
-
-	// We don't have a working preconfigured spool path, so we take the temp path.
-	$temppath = get_temppath();
-
-	if ($temppath != "") {
-		// To avoid any interferences with other systems we create our own directory
-		$spoolpath = $temppath . "/spool";
-		if (!is_dir($spoolpath)) {
-			mkdir($spoolpath);
-		}
-
-		if (System::isDirectoryUsable($spoolpath)) {
-			// The new path is usable, we are happy
-			DI::config()->set("system", "spoolpath", $spoolpath);
-			return $spoolpath;
-		} else {
-			// We can't create a subdirectory, strange.
-			// But the directory seems to work, so we use it but don't store it.
-			return $temppath;
-		}
-	}
-
-	// Reaching this point means that the operating system is configured badly.
-	return "";
-}
-
-if (!function_exists('exif_imagetype')) {
-	function exif_imagetype($file)
-	{
-		$size = getimagesize($file);
-		return $size[2];
-	}
-}
-
-function validate_include(&$file)
-{
-	$orig_file = $file;
-
-	$file = realpath($file);
-
-	if (strpos($file, getcwd()) !== 0) {
-		return false;
-	}
-
-	$file = str_replace(getcwd() . "/", "", $file, $count);
-	if ($count != 1) {
-		return false;
-	}
-
-	if ($orig_file !== $file) {
-		return false;
-	}
-
-	$valid = false;
-	if (strpos($file, "include/") === 0) {
-		$valid = true;
-	}
-
-	if (strpos($file, "addon/") === 0) {
-		$valid = true;
-	}
-
-	// Simply return flag
-	return $valid;
-}
diff --git a/include/api.php b/include/api.php
index 6a00268b04..2495f5d192 100644
--- a/include/api.php
+++ b/include/api.php
@@ -4604,9 +4604,6 @@ function save_media_to_database($mediatype, $media, $type, $album, $allow_cid, $
 
 	// check max length of images on server
 	$max_length = DI::config()->get('system', 'max_image_length');
-	if (!$max_length) {
-		$max_length = MAX_IMAGE_LENGTH;
-	}
 	if ($max_length > 0) {
 		$Image->scaleDown($max_length);
 		logger::info("File upload: Scaling picture to new size " . $max_length);
diff --git a/mod/photos.php b/mod/photos.php
index 2efd3a5a7a..5ca9aa600a 100644
--- a/mod/photos.php
+++ b/mod/photos.php
@@ -703,9 +703,6 @@ function photos_post(App $a)
 	@unlink($src);
 
 	$max_length = DI::config()->get('system', 'max_image_length');
-	if (!$max_length) {
-		$max_length = MAX_IMAGE_LENGTH;
-	}
 	if ($max_length > 0) {
 		$image->scaleDown($max_length);
 	}
diff --git a/mod/ping.php b/mod/ping.php
index c12594902a..fce4cbcf01 100644
--- a/mod/ping.php
+++ b/mod/ping.php
@@ -196,7 +196,7 @@ function ping_init(App $a)
 		$myurl = DI::baseUrl() . '/profile/' . $a->getLoggedInUserNickname();
 		$mail_count = DBA::count('mail', ["`uid` = ? AND NOT `seen` AND `from-url` != ?", local_user(), $myurl]);
 
-		if (intval(DI::config()->get('config', 'register_policy')) === \Friendica\Module\Register::APPROVE && is_site_admin()) {
+		if (intval(DI::config()->get('config', 'register_policy')) === \Friendica\Module\Register::APPROVE && $a->isSiteAdmin()) {
 			$regs = Friendica\Model\Register::getPending();
 
 			if (DBA::isResult($regs)) {
diff --git a/mod/settings.php b/mod/settings.php
index e84917c35c..d3fbd81db8 100644
--- a/mod/settings.php
+++ b/mod/settings.php
@@ -492,7 +492,7 @@ function settings_content(App $a)
 		$settings_connectors = '';
 		Hook::callAll('connector_settings', $settings_connectors);
 
-		if (is_site_admin()) {
+		if ($a->isSiteAdmin()) {
 			$diasp_enabled = DI::l10n()->t('Built-in support for %s connectivity is %s', DI::l10n()->t('Diaspora (Socialhome, Hubzilla)'), ((DI::config()->get('system', 'diaspora_enabled')) ? DI::l10n()->t('enabled') : DI::l10n()->t('disabled')));
 			$ostat_enabled = DI::l10n()->t('Built-in support for %s connectivity is %s', DI::l10n()->t('OStatus (GNU Social)'), ((DI::config()->get('system', 'ostatus_disabled')) ? DI::l10n()->t('disabled') : DI::l10n()->t('enabled')));
 		} else {
diff --git a/mod/uimport.php b/mod/uimport.php
index 62bece5e3a..a00bf25087 100644
--- a/mod/uimport.php
+++ b/mod/uimport.php
@@ -29,7 +29,7 @@ use Friendica\DI;
 
 function uimport_post(App $a)
 {
-	if ((DI::config()->get('config', 'register_policy') != \Friendica\Module\Register::OPEN) && !is_site_admin()) {
+	if ((DI::config()->get('config', 'register_policy') != \Friendica\Module\Register::OPEN) && !$a->isSiteAdmin()) {
 		notice(DI::l10n()->t('Permission denied.'));
 		return;
 	}
@@ -42,7 +42,7 @@ function uimport_post(App $a)
 
 function uimport_content(App $a)
 {
-	if ((DI::config()->get('config', 'register_policy') != \Friendica\Module\Register::OPEN) && !is_site_admin()) {
+	if ((DI::config()->get('config', 'register_policy') != \Friendica\Module\Register::OPEN) && !$a->isSiteAdmin()) {
 		notice(DI::l10n()->t('User imports on closed servers can only be done by an administrator.'));
 		return;
 	}
diff --git a/mod/wall_upload.php b/mod/wall_upload.php
index 38819c9a58..fd88ab2bc2 100644
--- a/mod/wall_upload.php
+++ b/mod/wall_upload.php
@@ -177,9 +177,6 @@ function wall_upload_post(App $a, $desktopmode = true)
 	@unlink($src);
 
 	$max_length = DI::config()->get('system', 'max_image_length');
-	if (!$max_length) {
-		$max_length = MAX_IMAGE_LENGTH;
-	}
 	if ($max_length > 0) {
 		$Image->scaleDown($max_length);
 		$filesize = strlen($Image->asString());
diff --git a/src/App.php b/src/App.php
index 44a5eb40df..dd84883887 100644
--- a/src/App.php
+++ b/src/App.php
@@ -154,6 +154,20 @@ class App
 		return local_user() && $this->user_id && ($this->user_id == local_user());
 	}
 
+	/**
+	 * Check if current user has admin role.
+	 *
+	 * @return bool true if user is an admin
+	 */
+	public function isSiteAdmin()
+	{
+		$admin_email = $this->config->get('config', 'admin_email');
+
+		$adminlist = explode(',', str_replace(' ', '', $admin_email));
+
+		return local_user() && $admin_email && $this->database->exists('user', ['uid' => $this->getLoggedInUserId(), 'email' => $adminlist]);
+	}
+
 	/**
 	 * Fetch the user id
 	 * @return int 
diff --git a/src/App/Page.php b/src/App/Page.php
index 578f9ab3e3..fcb2d18533 100644
--- a/src/App/Page.php
+++ b/src/App/Page.php
@@ -257,6 +257,28 @@ class Page implements ArrayAccess
 		]) . $this->page['htmlhead'];
 	}
 
+	/**
+	 * Returns the complete URL of the current page, e.g.: http(s)://something.com/network
+	 *
+	 * Taken from http://webcheatsheet.com/php/get_current_page_url.php
+	 */
+	private function curPageURL()
+	{
+		$pageURL = 'http';
+		if (!empty($_SERVER["HTTPS"]) && ($_SERVER["HTTPS"] == "on")) {
+			$pageURL .= "s";
+		}
+	
+		$pageURL .= "://";
+	
+		if ($_SERVER["SERVER_PORT"] != "80" && $_SERVER["SERVER_PORT"] != "443") {
+			$pageURL .= $_SERVER["SERVER_NAME"] . ":" . $_SERVER["SERVER_PORT"] . $_SERVER["REQUEST_URI"];
+		} else {
+			$pageURL .= $_SERVER["SERVER_NAME"] . $_SERVER["REQUEST_URI"];
+		}
+		return $pageURL;
+	}
+      
 	/**
 	 * Initializes Page->page['footer'].
 	 *
@@ -290,9 +312,9 @@ class Page implements ArrayAccess
 		 */
 		if ($mode->isMobile() || $mode->isTablet()) {
 			if (isset($_SESSION['show-mobile']) && !$_SESSION['show-mobile']) {
-				$link = 'toggle_mobile?address=' . urlencode(curPageURL());
+				$link = 'toggle_mobile?address=' . urlencode($this->curPageURL());
 			} else {
-				$link = 'toggle_mobile?off=1&address=' . urlencode(curPageURL());
+				$link = 'toggle_mobile?off=1&address=' . urlencode($this->curPageURL());
 			}
 			$this->page['footer'] .= Renderer::replaceMacros(Renderer::getMarkupTemplate("toggle_mobile_footer.tpl"), [
 				'$toggle_link' => $link,
diff --git a/src/Content/Conversation.php b/src/Content/Conversation.php
index 7bd7ea69fb..d8cbbf7cbb 100644
--- a/src/Content/Conversation.php
+++ b/src/Content/Conversation.php
@@ -223,12 +223,12 @@ class Conversation
 					break;
 			}
 		} elseif ($total > 1) {
-			if ($total < MAX_LIKERS) {
+			if ($total < $this->config->get('system', 'max_likers')) {
 				$likers = implode(', ', array_slice($links, 0, -1));
 				$likers .= ' ' . $this->l10n->t('and') . ' ' . $links[count($links) - 1];
 			} else {
-				$likers = implode(', ', array_slice($links, 0, MAX_LIKERS - 1));
-				$likers .= ' ' . $this->l10n->t('and %d other people', $total - MAX_LIKERS);
+				$likers = implode(', ', array_slice($links, 0, $this->config->get('system', 'max_likers') - 1));
+				$likers .= ' ' . $this->l10n->t('and %d other people', $total - $this->config->get('system', 'max_likers'));
 			}
 
 			$spanatts = "class=\"fakelink\" onclick=\"openClose('{$verb}list-$id');\"";
diff --git a/src/Content/Nav.php b/src/Content/Nav.php
index 90822c7e6f..506e71623c 100644
--- a/src/Content/Nav.php
+++ b/src/Content/Nav.php
@@ -295,7 +295,7 @@ class Nav
 		}
 
 		// Show the link to the admin configuration page if user is admin
-		if (is_site_admin()) {
+		if ($a->isSiteAdmin()) {
 			$nav['admin'] = ['admin/', DI::l10n()->t('Admin'), '', DI::l10n()->t('Site setup and configuration')];
 		}
 
diff --git a/src/Content/Widget.php b/src/Content/Widget.php
index 4a3e918674..8ec57dce40 100644
--- a/src/Content/Widget.php
+++ b/src/Content/Widget.php
@@ -63,7 +63,7 @@ class Widget
 
 		if (DI::config()->get('system', 'invitation_only')) {
 			$x = intval(DI::pConfig()->get(local_user(), 'system', 'invites_remaining'));
-			if ($x || is_site_admin()) {
+			if ($x || DI::app()->isSiteAdmin()) {
 				DI::page()['aside'] .= '<div class="side-link widget" id="side-invite-remain">'
 					. DI::l10n()->tt('%d invitation available', '%d invitations available', $x)
 					. '</div>';
diff --git a/src/Core/Lock/Type/SemaphoreLock.php b/src/Core/Lock/Type/SemaphoreLock.php
index f68b5546cd..198e8dcc41 100644
--- a/src/Core/Lock/Type/SemaphoreLock.php
+++ b/src/Core/Lock/Type/SemaphoreLock.php
@@ -24,7 +24,7 @@ namespace Friendica\Core\Lock\Type;
 use Friendica\Core\Cache\Enum\Duration;
 use Friendica\Core\Lock\Enum\Type;
 use Friendica\Core\Lock\Exception\InvalidLockDriverException;
-use function get_temppath;
+use Friendica\Core\System;
 
 class SemaphoreLock extends AbstractLock
 {
@@ -44,7 +44,7 @@ class SemaphoreLock extends AbstractLock
 	{
 		$success = true;
 
-		$temp = get_temppath();
+		$temp = System::getTempPath();
 
 		$file = $temp . '/' . $key . '.sem';
 
diff --git a/src/Core/Renderer.php b/src/Core/Renderer.php
index 4eb4084728..608c707434 100644
--- a/src/Core/Renderer.php
+++ b/src/Core/Renderer.php
@@ -84,7 +84,7 @@ class Renderer
 			$output = $t->replaceMacros($template, $vars);
 		} catch (Exception $e) {
 			DI::logger()->critical($e->getMessage(), ['template' => $template, 'vars' => $vars]);
-			$message = is_site_admin() ?
+			$message = DI::app()->isSiteAdmin() ?
 				$e->getMessage() :
 				DI::l10n()->t('Friendica can\'t display this page at the moment, please contact the administrator.');
 			throw new ServiceUnavailableException($message);
@@ -113,7 +113,7 @@ class Renderer
 			$template = $t->getTemplateFile($file, $subDir);
 		} catch (Exception $e) {
 			DI::logger()->critical($e->getMessage(), ['file' => $file, 'subDir' => $subDir]);
-			$message = is_site_admin() ?
+			$message = DI::app()->isSiteAdmin() ?
 				$e->getMessage() :
 				DI::l10n()->t('Friendica can\'t display this page at the moment, please contact the administrator.');
 			throw new ServiceUnavailableException($message);
@@ -140,7 +140,7 @@ class Renderer
 		} else {
 			$admin_message = DI::l10n()->t('template engine cannot be registered without a name.');
 			DI::logger()->critical($admin_message, ['class' => $class]);
-			$message = is_site_admin() ?
+			$message = DI::app()->isSiteAdmin() ?
 				$admin_message :
 				DI::l10n()->t('Friendica can\'t display this page at the moment, please contact the administrator.');
 			throw new ServiceUnavailableException($message);
@@ -174,7 +174,7 @@ class Renderer
 
 		$admin_message = DI::l10n()->t('template engine is not registered!');
 		DI::logger()->critical($admin_message, ['template_engine' => $template_engine]);
-		$message = is_site_admin() ?
+		$message = DI::app()->isSiteAdmin() ?
 			$admin_message :
 			DI::l10n()->t('Friendica can\'t display this page at the moment, please contact the administrator.');
 		throw new ServiceUnavailableException($message);
diff --git a/src/Core/System.php b/src/Core/System.php
index f680b6530d..2cc9a48bc3 100644
--- a/src/Core/System.php
+++ b/src/Core/System.php
@@ -21,10 +21,12 @@
 
 namespace Friendica\Core;
 
+use Exception;
 use Friendica\DI;
 use Friendica\Network\HTTPException\FoundException;
 use Friendica\Network\HTTPException\MovedPermanentlyException;
 use Friendica\Network\HTTPException\TemporaryRedirectException;
+use Friendica\Util\BasePath;
 use Friendica\Util\XML;
 
 /**
@@ -323,15 +325,85 @@ class System
 		exit();
 	}
 
-	/// @todo Move the following functions from boot.php
-	/*
-	function local_user()
-	function public_contact()
-	function remote_user()
-	function notice($s)
-	function info($s)
-	function is_site_admin()
-	function get_temppath()
-	function get_spoolpath()
-	*/
+	/**
+	 * Fetch the temp path of the system
+	 *
+	 * @return string Path for temp files
+	 */
+	public static function getTempPath()
+	{
+		$temppath = DI::config()->get("system", "temppath");
+
+		if (($temppath != "") && System::isDirectoryUsable($temppath)) {
+			// We have a temp path and it is usable
+			return BasePath::getRealPath($temppath);
+		}
+
+		// We don't have a working preconfigured temp path, so we take the system path.
+		$temppath = sys_get_temp_dir();
+
+		// Check if it is usable
+		if (($temppath != "") && System::isDirectoryUsable($temppath)) {
+			// Always store the real path, not the path through symlinks
+			$temppath = BasePath::getRealPath($temppath);
+
+			// To avoid any interferences with other systems we create our own directory
+			$new_temppath = $temppath . "/" . DI::baseUrl()->getHostname();
+			if (!is_dir($new_temppath)) {
+				/// @TODO There is a mkdir()+chmod() upwards, maybe generalize this (+ configurable) into a function/method?
+				mkdir($new_temppath);
+			}
+
+			if (System::isDirectoryUsable($new_temppath)) {
+				// The new path is usable, we are happy
+				DI::config()->set("system", "temppath", $new_temppath);
+				return $new_temppath;
+			} else {
+				// We can't create a subdirectory, strange.
+				// But the directory seems to work, so we use it but don't store it.
+				return $temppath;
+			}
+		}
+
+		// Reaching this point means that the operating system is configured badly.
+		return '';
+	}
+
+	/**
+	 * Returns the path where spool files are stored
+	 *
+	 * @return string Spool path
+	 */
+	public static function getSpoolPath()
+	{
+		$spoolpath = DI::config()->get('system', 'spoolpath');
+		if (($spoolpath != "") && System::isDirectoryUsable($spoolpath)) {
+			// We have a spool path and it is usable
+			return $spoolpath;
+		}
+
+		// We don't have a working preconfigured spool path, so we take the temp path.
+		$temppath = self::getTempPath();
+
+		if ($temppath != "") {
+			// To avoid any interferences with other systems we create our own directory
+			$spoolpath = $temppath . "/spool";
+			if (!is_dir($spoolpath)) {
+				mkdir($spoolpath);
+			}
+
+			if (System::isDirectoryUsable($spoolpath)) {
+				// The new path is usable, we are happy
+				DI::config()->set("system", "spoolpath", $spoolpath);
+				return $spoolpath;
+			} else {
+				// We can't create a subdirectory, strange.
+				// But the directory seems to work, so we use it but don't store it.
+				return $temppath;
+			}
+		}
+
+		// Reaching this point means that the operating system is configured badly.
+		return "";
+	}
 }
diff --git a/src/Core/Worker.php b/src/Core/Worker.php
index 0431c79521..3d1648ea45 100644
--- a/src/Core/Worker.php
+++ b/src/Core/Worker.php
@@ -277,6 +277,44 @@ class Worker
 		return DBA::exists('workerqueue', $condition);
 	}
 
+	/**
+	 * Checks if the given file is valid to be included
+	 *
+	 * @param mixed $file 
+	 * @return bool 
+	 */
+	private static function validateInclude(&$file)
+	{
+		$orig_file = $file;
+	
+		$file = realpath($file);
+	
+		if (strpos($file, getcwd()) !== 0) {
+			return false;
+		}
+	
+		$file = str_replace(getcwd() . "/", "", $file, $count);
+		if ($count != 1) {
+			return false;
+		}
+	
+		if ($orig_file !== $file) {
+			return false;
+		}
+	
+		$valid = false;
+		if (strpos($file, "include/") === 0) {
+			$valid = true;
+		}
+	
+		if (strpos($file, "addon/") === 0) {
+			$valid = true;
+		}
+	
+		// Simply return flag
+		return $valid;
+	}
+	
 	/**
 	 * Execute a worker entry
 	 *
@@ -360,7 +398,7 @@ class Worker
 			$include = "include/".$include.".php";
 		}
 
-		if (!validate_include($include)) {
+		if (!self::validateInclude($include)) {
 			Logger::warning("Include file is not valid", ['file' => $argv[0]]);
 			$stamp = (float)microtime(true);
 			DBA::delete('workerqueue', ['id' => $queue["id"]]);
diff --git a/src/Model/Item.php b/src/Model/Item.php
index 297506176a..094fa3b029 100644
--- a/src/Model/Item.php
+++ b/src/Model/Item.php
@@ -448,7 +448,7 @@ class Item
 		// We use "microtime" to keep the arrival order and "mt_rand" to avoid duplicates
 		$file = 'item-' . round(microtime(true) * 10000) . '-' . mt_rand() . '.msg';
 
-		$spoolpath = get_spoolpath();
+		$spoolpath = System::getSpoolPath();
 		if ($spoolpath != "") {
 			$spool = $spoolpath . '/' . $file;
 
diff --git a/src/Model/Photo.php b/src/Model/Photo.php
index 13beb05b3c..d27bac47ac 100644
--- a/src/Model/Photo.php
+++ b/src/Model/Photo.php
@@ -951,9 +951,6 @@ class Photo
 		@unlink($src);
 
 		$max_length = DI::config()->get('system', 'max_image_length');
-		if (!$max_length) {
-			$max_length = MAX_IMAGE_LENGTH;
-		}
 		if ($max_length > 0) {
 			$Image->scaleDown($max_length);
 			$filesize = strlen($Image->asString());
diff --git a/src/Model/User.php b/src/Model/User.php
index 65e64cb5cd..92f50dd25c 100644
--- a/src/Model/User.php
+++ b/src/Model/User.php
@@ -706,7 +706,7 @@ class User
 	{
 		$cache = new CacheItemPool();
 		$cache->changeConfig([
-			'cacheDirectory' => get_temppath() . '/password-exposed-cache/',
+			'cacheDirectory' => System::getTempPath() . '/password-exposed-cache/',
 		]);
 
 		try {
diff --git a/src/Module/ActivityPub/Inbox.php b/src/Module/ActivityPub/Inbox.php
index 36940cb2de..2ef12a83d8 100644
--- a/src/Module/ActivityPub/Inbox.php
+++ b/src/Module/ActivityPub/Inbox.php
@@ -23,6 +23,7 @@ namespace Friendica\Module\ActivityPub;
 
 use Friendica\BaseModule;
 use Friendica\Core\Logger;
+use Friendica\Core\System;
 use Friendica\Database\DBA;
 use Friendica\DI;
 use Friendica\Protocol\ActivityPub;
@@ -48,7 +49,7 @@ class Inbox extends BaseModule
 			} else {
 				$filename = 'failed-activitypub';
 			}
-			$tempfile = tempnam(get_temppath(), $filename);
+			$tempfile = tempnam(System::getTempPath(), $filename);
 			file_put_contents($tempfile, json_encode(['parameters' => $parameters, 'header' => $_SERVER, 'body' => $postdata], JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE));
 			Logger::notice('Incoming message stored', ['file' => $tempfile]);
 		}
diff --git a/src/Module/Admin/Site.php b/src/Module/Admin/Site.php
index 71deb67ef3..2cc4ac23a3 100644
--- a/src/Module/Admin/Site.php
+++ b/src/Module/Admin/Site.php
@@ -24,6 +24,7 @@ namespace Friendica\Module\Admin;
 use Friendica\App;
 use Friendica\Core\Renderer;
 use Friendica\Core\Search;
+use Friendica\Core\System;
 use Friendica\Core\Theme;
 use Friendica\Core\Worker;
 use Friendica\Database\DBA;
@@ -138,8 +139,8 @@ class Site extends BaseAdmin
 		$theme            = (!empty($_POST['theme'])            ? Strings::escapeTags(trim($_POST['theme']))         : '');
 		$theme_mobile     = (!empty($_POST['theme_mobile'])     ? Strings::escapeTags(trim($_POST['theme_mobile']))  : '');
 		$maximagesize     = (!empty($_POST['maximagesize'])     ? intval(trim($_POST['maximagesize']))               : 0);
-		$maximagelength   = (!empty($_POST['maximagelength'])   ? intval(trim($_POST['maximagelength']))             : MAX_IMAGE_LENGTH);
-		$jpegimagequality = (!empty($_POST['jpegimagequality']) ? intval(trim($_POST['jpegimagequality']))           : JPEG_QUALITY);
+		$maximagelength   = (!empty($_POST['maximagelength'])   ? intval(trim($_POST['maximagelength']))             : -1);
+		$jpegimagequality = (!empty($_POST['jpegimagequality']) ? intval(trim($_POST['jpegimagequality']))           : 100);
 
 		$register_policy        = (!empty($_POST['register_policy'])         ? intval(trim($_POST['register_policy']))             : 0);
 		$daily_registrations    = (!empty($_POST['max_daily_registrations']) ? intval(trim($_POST['max_daily_registrations']))     : 0);
@@ -463,7 +464,7 @@ class Site extends BaseAdmin
 		$additional_info = DI::config()->get('config', 'info');
 
 		// Automatically create temporary paths
-		get_temppath();
+		System::getTempPath();
 
 		/* Register policy */
 		$register_choices = [
@@ -609,7 +610,7 @@ class Site extends BaseAdmin
 			'$worker_fastlane'        => ['worker_fastlane', DI::l10n()->t('Enable fastlane'), DI::config()->get('system', 'worker_fastlane'), DI::l10n()->t('When enabed, the fastlane mechanism starts an additional worker if processes with higher priority are blocked by processes of lower priority.')],
 
 			'$relay_directly'         => ['relay_directly', DI::l10n()->t('Direct relay transfer'), DI::config()->get('system', 'relay_directly'), DI::l10n()->t('Enables the direct transfer to other servers without using the relay servers')],
-			'$relay_scope'            => ['relay_scope', DI::l10n()->t('Relay scope'), DI::config()->get('system', 'relay_scope'), DI::l10n()->t('Can be "all" or "tags". "all" means that every public post should be received. "tags" means that only posts with selected tags should be received.'), [SR_SCOPE_NONE => DI::l10n()->t('Disabled'), SR_SCOPE_ALL => DI::l10n()->t('all'), SR_SCOPE_TAGS => DI::l10n()->t('tags')]],
+			'$relay_scope'            => ['relay_scope', DI::l10n()->t('Relay scope'), DI::config()->get('system', 'relay_scope'), DI::l10n()->t('Can be "all" or "tags". "all" means that every public post should be received. "tags" means that only posts with selected tags should be received.'), [Relay::SCOPE_NONE => DI::l10n()->t('Disabled'), Relay::SCOPE_ALL => DI::l10n()->t('all'), Relay::SCOPE_TAGS => DI::l10n()->t('tags')]],
 			'$relay_server_tags'      => ['relay_server_tags', DI::l10n()->t('Server tags'), DI::config()->get('system', 'relay_server_tags'), DI::l10n()->t('Comma separated list of tags for the "tags" subscription.')],
 			'$relay_deny_tags'        => ['relay_deny_tags', DI::l10n()->t('Deny Server tags'), DI::config()->get('system', 'relay_deny_tags'), DI::l10n()->t('Comma separated list of tags that are rejected.')],
 			'$relay_user_tags'        => ['relay_user_tags', DI::l10n()->t('Allow user tags'), DI::config()->get('system', 'relay_user_tags'), DI::l10n()->t('If enabled, the tags from the saved searches will used for the "tags" subscription in addition to the "relay_server_tags".')],
diff --git a/src/Module/BaseAdmin.php b/src/Module/BaseAdmin.php
index 5d5841f994..69c2879de6 100644
--- a/src/Module/BaseAdmin.php
+++ b/src/Module/BaseAdmin.php
@@ -59,7 +59,7 @@ abstract class BaseAdmin extends BaseModule
 			}
 		}
 
-		if (!is_site_admin()) {
+		if (!DI::app()->isSiteAdmin()) {
 			throw new HTTPException\ForbiddenException(DI::l10n()->t('You don\'t have access to administration pages.'));
 		}
 
diff --git a/src/Module/Invite.php b/src/Module/Invite.php
index 82b8c604a9..566e54b129 100644
--- a/src/Module/Invite.php
+++ b/src/Module/Invite.php
@@ -67,7 +67,7 @@ class Invite extends BaseModule
 		if ($config->get('system', 'invitation_only')) {
 			$invitation_only = true;
 			$invites_remaining = DI::pConfig()->get(local_user(), 'system', 'invites_remaining');
-			if ((!$invites_remaining) && (!is_site_admin())) {
+			if ((!$invites_remaining) && (!$app->isSiteAdmin())) {
 				throw new HTTPException\ForbiddenException();
 			}
 		}
@@ -82,11 +82,11 @@ class Invite extends BaseModule
 				continue;
 			}
 
-			if ($invitation_only && ($invites_remaining || is_site_admin())) {
+			if ($invitation_only && ($invites_remaining || $app->isSiteAdmin())) {
 				$code = Model\Register::createForInvitation();
 				$nmessage = str_replace('$invite_code', $code, $message);
 
-				if (!is_site_admin()) {
+				if (!$app->isSiteAdmin()) {
 					$invites_remaining--;
 					if ($invites_remaining >= 0) {
 						DI::pConfig()->set(local_user(), 'system', 'invites_remaining', $invites_remaining);
@@ -138,7 +138,7 @@ class Invite extends BaseModule
 		if ($config->get('system', 'invitation_only')) {
 			$inviteOnly = true;
 			$x = DI::pConfig()->get(local_user(), 'system', 'invites_remaining');
-			if ((!$x) && (!is_site_admin())) {
+			if ((!$x) && (!$app->isSiteAdmin())) {
 				throw new HTTPException\ForbiddenException(DI::l10n()->t('You have no more invitations available'));
 			}
 		}
diff --git a/src/Module/Special/HTTPException.php b/src/Module/Special/HTTPException.php
index 8fe4c8ce57..3b771c3ac7 100644
--- a/src/Module/Special/HTTPException.php
+++ b/src/Module/Special/HTTPException.php
@@ -51,7 +51,7 @@ class HTTPException
 			'$stack_trace' => DI::l10n()->t('Stack trace:'),
 		];
 
-		if (is_site_admin()) {
+		if (DI::app()->isSiteAdmin()) {
 			$vars['$thrown'] = DI::l10n()->t('Exception thrown in %s:%d', $e->getFile(), $e->getLine());
 			$vars['$trace'] = $e->getTraceAsString();
 		}
diff --git a/src/Module/WellKnown/XSocialRelay.php b/src/Module/WellKnown/XSocialRelay.php
index 15b8e276ad..96968680dc 100644
--- a/src/Module/WellKnown/XSocialRelay.php
+++ b/src/Module/WellKnown/XSocialRelay.php
@@ -24,6 +24,7 @@ namespace Friendica\Module\WellKnown;
 use Friendica\BaseModule;
 use Friendica\DI;
 use Friendica\Model\Search;
+use Friendica\Protocol\Relay;
 
 /**
  * Node subscription preferences for social realy systems
@@ -40,7 +41,7 @@ class XSocialRelay extends BaseModule
 		$systemTags = [];
 		$userTags = [];
 
-		if ($scope == SR_SCOPE_TAGS) {
+		if ($scope == Relay::SCOPE_TAGS) {
 			$server_tags = $config->get('system', 'relay_server_tags');
 			$tagitems = explode(',', $server_tags);
 
@@ -57,7 +58,7 @@ class XSocialRelay extends BaseModule
 		$tagList = array_unique(array_merge($systemTags, $userTags));
 
 		$relay = [
-			'subscribe' => ($scope != SR_SCOPE_NONE),
+			'subscribe' => ($scope != Relay::SCOPE_NONE),
 			'scope'     => $scope,
 			'tags'      => $tagList,
 			'protocols' => [
diff --git a/src/Network/HTTPClient/Factory/HttpClient.php b/src/Network/HTTPClient/Factory/HttpClient.php
index c7ee68a926..18fc73ab88 100644
--- a/src/Network/HTTPClient/Factory/HttpClient.php
+++ b/src/Network/HTTPClient/Factory/HttpClient.php
@@ -5,6 +5,7 @@ namespace Friendica\Network\HTTPClient\Factory;
 use Friendica\App;
 use Friendica\BaseFactory;
 use Friendica\Core\Config\Capability\IManageConfigValues;
+use Friendica\Core\System;
 use Friendica\Network\HTTPClient\Client;
 use Friendica\Network\HTTPClient\Capability\ICanSendHttpRequests;
 use Friendica\Util\Profiler;
@@ -106,7 +107,7 @@ class HttpClient extends BaseFactory
 		$resolver->setMaxResponseDataSize(1000000);
 		// Designate a temporary file that will store cookies during the session.
 		// Some websites test the browser for cookie support, so this enhances results.
-		$resolver->setCookieJar(get_temppath() .'/resolver-cookie-' . Strings::getRandomName(10));
+		$resolver->setCookieJar(System::getTempPath() .'/resolver-cookie-' . Strings::getRandomName(10));
 
 		return new Client\HttpClient($logger, $this->profiler, $guzzle, $resolver);
 	}
diff --git a/src/Object/Image.php b/src/Object/Image.php
index dd95903696..4551db248c 100644
--- a/src/Object/Image.php
+++ b/src/Object/Image.php
@@ -134,9 +134,6 @@ class Image
 			switch ($this->getType()) {
 				case "image/png":
 					$quality = DI::config()->get('system', 'png_quality');
-					if ((! $quality) || ($quality > 9)) {
-						$quality = PNG_QUALITY;
-					}
 					/*
 					 * From http://www.imagemagick.org/script/command-line-options.php#quality:
 					 *
@@ -150,9 +147,6 @@ class Image
 					break;
 				case "image/jpeg":
 					$quality = DI::config()->get('system', 'jpeg_quality');
-					if ((! $quality) || ($quality > 100)) {
-						$quality = JPEG_QUALITY;
-					}
 					$this->image->setCompressionQuality($quality);
 			}
 
@@ -680,16 +674,10 @@ class Image
 		switch ($this->getType()) {
 			case "image/png":
 				$quality = DI::config()->get('system', 'png_quality');
-				if ((!$quality) || ($quality > 9)) {
-					$quality = PNG_QUALITY;
-				}
 				imagepng($this->image, null, $quality);
 				break;
 			case "image/jpeg":
 				$quality = DI::config()->get('system', 'jpeg_quality');
-				if ((!$quality) || ($quality > 100)) {
-					$quality = JPEG_QUALITY;
-				}
 				imagejpeg($this->image, null, $quality);
 		}
 		$string = ob_get_contents();
diff --git a/src/Protocol/DFRN.php b/src/Protocol/DFRN.php
index ac51e104a9..79a90d403c 100644
--- a/src/Protocol/DFRN.php
+++ b/src/Protocol/DFRN.php
@@ -413,6 +413,48 @@ class DFRN
 		return $root;
 	}
 
+	/**
+	 * Determine the next birthday, but only if the birthday is published
+	 * in the default profile. We _could_ also look for a private profile that the
+	 * recipient can see, but somebody could get mad at us if they start getting
+	 * public birthday greetings when they haven't made this info public.
+	 *
+	 * Assuming we are able to publish this info, we are then going to convert
+	 * the start time from the owner's timezone to UTC.
+	 *
+	 * This will potentially solve the problem found with some social networks
+	 * where birthdays are converted to the viewer's timezone and salutations from
+	 * elsewhere in the world show up on the wrong day. We will convert it to the
+	 * viewer's timezone also, but first we are going to convert it from the birthday
+	 * person's timezone to GMT - so the viewer may find the birthday starting at
+	 * 6:00PM the day before, but that will correspond to midnight to the birthday person.
+	 */
+	private static function determineNextBirthday($uid, $tz)
+	{
+		$birthday = '';
+
+		if (!strlen($tz)) {
+			$tz = 'UTC';
+		}
+
+		$profile = DBA::selectFirst('profile', ['dob'], ['uid' => $uid]);
+		if (DBA::isResult($profile)) {
+			$tmp_dob = substr($profile['dob'], 5);
+			if (intval($tmp_dob)) {
+				$y = DateTimeFormat::timezoneNow($tz, 'Y');
+				$bd = $y . '-' . $tmp_dob . ' 00:00';
+				$t_dob = strtotime($bd);
+				$now = strtotime(DateTimeFormat::timezoneNow($tz));
+				if ($t_dob < $now) {
+					$bd = $y + 1 . '-' . $tmp_dob . ' 00:00';
+				}
+				$birthday = DateTimeFormat::convert($bd, 'UTC', $tz, DateTimeFormat::ATOM);
+			}
+		}
+
+		return $birthday;
+	}
+
 	/**
 	 * Adds the author element in the header for the DFRN protocol
 	 *
@@ -467,7 +509,7 @@ class DFRN
 			return $author;
 		}
 
-		$birthday = feed_birthday($owner['uid'], $owner['timezone']);
+		$birthday = self::determineNextBirthday($owner['uid'], $owner['timezone']);
 
 		if ($birthday) {
 			XML::addElement($doc, $author, "dfrn:birthday", $birthday);
diff --git a/src/Protocol/Relay.php b/src/Protocol/Relay.php
index da9a2e3923..d98fda46d7 100644
--- a/src/Protocol/Relay.php
+++ b/src/Protocol/Relay.php
@@ -37,9 +37,15 @@ use Friendica\Util\Strings;
 
 /**
  * Base class for relay handling
+ * @see https://github.com/jaywink/social-relay
+ * @see https://wiki.diasporafoundation.org/Relay_servers_for_public_posts
  */
 class Relay
 {
+	const SCOPE_NONE = '';
+	const SCOPE_ALL = 'all';
+	const SCOPE_TAGS = 'tags';
+
 	/**
 	 * Check if a post is wanted
 	 *
@@ -55,7 +61,7 @@ class Relay
 
 		$scope = $config->get('system', 'relay_scope');
 
-		if ($scope == SR_SCOPE_NONE) {
+		if ($scope == self::SCOPE_NONE) {
 			Logger::info('Server does not accept relay posts - rejected', ['network' => $network, 'url' => $url]);
 			return false;
 		}
@@ -74,7 +80,7 @@ class Relay
 		$userTags = [];
 		$denyTags = [];
 
-		if ($scope == SR_SCOPE_TAGS) {
+		if ($scope == self::SCOPE_TAGS) {
 			$server_tags = $config->get('system', 'relay_server_tags');
 			$tagitems = explode(',', mb_strtolower($server_tags));
 			foreach ($tagitems as $tag) {
@@ -119,7 +125,7 @@ class Relay
 			}
 		}
 
-		if ($scope == SR_SCOPE_ALL) {
+		if ($scope == self::SCOPE_ALL) {
 			Logger::info('Server accept all posts - accepted', ['network' => $network, 'url' => $url]);
 			return true;
 		}
diff --git a/src/Render/FriendicaSmartyEngine.php b/src/Render/FriendicaSmartyEngine.php
index c336273c72..e482b70e64 100644
--- a/src/Render/FriendicaSmartyEngine.php
+++ b/src/Render/FriendicaSmartyEngine.php
@@ -51,7 +51,7 @@ final class FriendicaSmartyEngine extends TemplateEngine
 		if (!is_writable(DI::basePath() . '/view/smarty3')) {
 			$admin_message = DI::l10n()->t('The folder view/smarty3/ must be writable by webserver.');
 			DI::logger()->critical($admin_message);
-			$message = is_site_admin() ?
+			$message = DI::app()->isSiteAdmin() ?
 				$admin_message :
 				DI::l10n()->t('Friendica can\'t display this page at the moment, please contact the administrator.');
 			throw new ServiceUnavailableException($message);
diff --git a/src/Worker/OnePoll.php b/src/Worker/OnePoll.php
index 1b5fdaa343..a5567841e1 100644
--- a/src/Worker/OnePoll.php
+++ b/src/Worker/OnePoll.php
@@ -23,6 +23,7 @@ namespace Friendica\Worker;
 
 use Friendica\Core\Logger;
 use Friendica\Core\Protocol;
+use Friendica\Core\System;
 use Friendica\Database\DBA;
 use Friendica\DI;
 use Friendica\Model\Contact;
@@ -152,7 +153,7 @@ class OnePoll
 			return false;
 		}
 
-		$cookiejar = tempnam(get_temppath(), 'cookiejar-onepoll-');
+		$cookiejar = tempnam(System::getTempPath(), 'cookiejar-onepoll-');
 		$curlResult = DI::httpClient()->get($contact['poll'], [HttpClientOptions::COOKIEJAR => $cookiejar]);
 		unlink($cookiejar);
 
diff --git a/src/Worker/SpoolPost.php b/src/Worker/SpoolPost.php
index e32cee1f2f..9501dc64a4 100644
--- a/src/Worker/SpoolPost.php
+++ b/src/Worker/SpoolPost.php
@@ -22,6 +22,7 @@
 namespace Friendica\Worker;
 
 use Friendica\Core\Logger;
+use Friendica\Core\System;
 use Friendica\Model\Item;
 
 /**
@@ -29,7 +30,7 @@ use Friendica\Model\Item;
  */
 class SpoolPost {
 	public static function execute() {
-		$path = get_spoolpath();
+		$path = System::getSpoolPath();
 
 		if (($path != '') && is_writable($path)){
 			if ($dh = opendir($path)) {
diff --git a/static/defaults.config.php b/static/defaults.config.php
index 0d25a1751a..0cfc2f6582 100644
--- a/static/defaults.config.php
+++ b/static/defaults.config.php
@@ -295,6 +295,12 @@ return [
 		// on detected mobile devices
 		'itemspage_network_mobile' => 20,
 
+		// jpeg_quality (Integer)
+		// 
+		// Lower numbers save space at cost of image detail
+		// where n is between 1 and 100, and with very poor results below about 50
+		'jpeg_quality' => 100,
+
 		// like_no_comment (Boolean)
 		// Don't update the "commented" value of an item when it is liked.
 		'like_no_comment' => false,
@@ -359,6 +365,10 @@ return [
 		// If you don't want to set a maximum length, set to -1.
 		'max_image_length' => -1,
 
+		// max_likers (Integer)
+		// Maximum number of "people who like (or don't like) this"  that we will list by name
+		'max_likers' => 75,
+
 		// max_processes_backend (Integer)
 		// Maximum number of concurrent database processes for background tasks.
 		'max_processes_backend' => 5,
diff --git a/static/settings.config.php b/static/settings.config.php
index 5530163dc8..e3a7a10a2c 100644
--- a/static/settings.config.php
+++ b/static/settings.config.php
@@ -176,9 +176,9 @@ return [
 		// Directly transmit content to relay subscribers without using a relay server
 		'relay_directly' => false,
 
-		// relay_scope (SR_SCOPE_NONE, SR_SCOPE_TAGS or SR_SCOPE_ALL)
+		// relay_scope (Relay::SCOPE_NONE, Relay::SCOPE_TAGS or Relay::SCOPE_ALL)
 		// Defines the scope of accepted posts from the relay servers
-		'relay_scope' => SR_SCOPE_NONE,
+		'relay_scope' => '',
 
 		// relay_server_tags (String)
 		// Comma separated list of tags for the "tags" subscription.
diff --git a/tests/datasets/config/.htconfig.php b/tests/datasets/config/.htconfig.php
index 7ab35bb28e..696ca5a03c 100644
--- a/tests/datasets/config/.htconfig.php
+++ b/tests/datasets/config/.htconfig.php
@@ -31,7 +31,7 @@ $a->config['sitename'] = "Friendica My Network";
 // and/or approve/deny the request.
 // In order to perform system administration via the admin panel, admin_email
 // must precisely match the email address of the person logged in.
-$a->config['register_policy'] = REGISTER_OPEN;
+$a->config['register_policy'] = Friendica\Module\Register::OPEN;
 $a->config['register_text'] = 'A register text';
 $a->config['admin_email'] = 'admin@test.it';
 $a->config['admin_nickname'] = 'Friendly admin';
diff --git a/tests/src/Core/Lock/SemaphoreLockTest.php b/tests/src/Core/Lock/SemaphoreLockTest.php
index 17e83a37d3..02cd447090 100644
--- a/tests/src/Core/Lock/SemaphoreLockTest.php
+++ b/tests/src/Core/Lock/SemaphoreLockTest.php
@@ -26,6 +26,7 @@ use Friendica\App;
 use Friendica\Core\Config\Capability\IManageConfigValues;
 use Friendica\Core\Config\Type\JitConfig;
 use Friendica\Core\Lock\Type\SemaphoreLock;
+use Friendica\Core\System;
 use Friendica\DI;
 use Mockery;
 use Mockery\MockInterface;
@@ -73,7 +74,7 @@ class SemaphoreLockTest extends LockTest
 	 */
 	public function testMissingFileNotOverriding()
 	{
-		$file = get_temppath() . '/test.sem';
+		$file = System::getTempPath() . '/test.sem';
 		touch($file);
 
 		self::assertTrue(file_exists($file));
@@ -91,7 +92,7 @@ class SemaphoreLockTest extends LockTest
 	 */
 	public function testMissingFileOverriding()
 	{
-		$file = get_temppath() . '/test.sem';
+		$file = System::getTempPath() . '/test.sem';
 		touch($file);
 
 		self::assertTrue(file_exists($file));
@@ -104,7 +105,7 @@ class SemaphoreLockTest extends LockTest
 	 */
 	public function testOverrideSemFile()
 	{
-		$file = get_temppath() . '/test.sem';
+		$file = System::getTempPath() . '/test.sem';
 		touch($file);
 
 		self::assertTrue(file_exists($file));
diff --git a/view/theme/frio/config.php b/view/theme/frio/config.php
index 38334e1d18..ee4f036607 100644
--- a/view/theme/frio/config.php
+++ b/view/theme/frio/config.php
@@ -57,7 +57,7 @@ function theme_post(App $a)
 
 function theme_admin_post(App $a)
 {
-	if (!is_site_admin()) {
+	if (!$a->isSiteAdmin()) {
 		return;
 	}