Replace existing autoloader with Composer-supplied

- Move Friendica namespace to `src`
- Move required `ezyang/htmlpurifier` to vendor
- Remove existing static autoloader
- Change boot.php reference to the autoloader

vendor/ezyang/htmlpurifier/plugins/phorum/settings.php

@@ -0,0 +1,64 @@
+<?php
+
+// based off of BBCode's settings file
+
+/**
+ * HTML Purifier Phorum mod settings configuration. This provides
+ * a convenient web-interface for editing the most common HTML Purifier
+ * configuration directives. You can also specify custom configuration
+ * by creating a 'config.php' file.
+ */
+
+if(!defined("PHORUM_ADMIN")) exit;
+
+// error reporting is good!
+error_reporting(E_ALL ^ E_NOTICE);
+
+// load library and other paraphenalia
+require_once './include/admin/PhorumInputForm.php';
+require_once (dirname(__FILE__) . '/htmlpurifier/HTMLPurifier.auto.php');
+require_once (dirname(__FILE__) . '/init-config.php');
+require_once (dirname(__FILE__) . '/settings/migrate-sigs-form.php');
+require_once (dirname(__FILE__) . '/settings/migrate-sigs.php');
+require_once (dirname(__FILE__) . '/settings/form.php');
+require_once (dirname(__FILE__) . '/settings/save.php');
+
+// define friendly configuration directives. you can expand this array
+// to get more web-definable directives
+$PHORUM['mod_htmlpurifier']['directives'] = array(
+    'URI.Host', // auto-detectable
+    'URI.DisableExternal',
+    'URI.DisableExternalResources',
+    'URI.DisableResources',
+    'URI.Munge',
+    'URI.HostBlacklist',
+    'URI.Disable',
+    'HTML.TidyLevel',
+    'HTML.Doctype', // auto-detectable
+    'HTML.Allowed',
+    'AutoFormat',
+    '-AutoFormat.Custom',
+    'AutoFormatParam',
+    'Output.TidyFormat',
+);
+
+// lower this setting if you're getting time outs/out of memory
+$PHORUM['mod_htmlpurifier']['migrate-sigs-increment'] = 100;
+
+if (isset($_POST['reset'])) {
+    unset($PHORUM['mod_htmlpurifier']['config']);
+}
+
+if ($offset = phorum_htmlpurifier_migrate_sigs_check()) {
+    // migrate signatures
+    phorum_htmlpurifier_migrate_sigs($offset);
+} elseif(!empty($_POST)){
+    // save settings
+    phorum_htmlpurifier_save_settings();
+}
+
+phorum_htmlpurifier_show_migrate_sigs_form();
+echo '<br />';
+phorum_htmlpurifier_show_form();
+
+// vim: et sw=4 sts=4