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/migrate-sigs.php

@@ -0,0 +1,79 @@
+<?php
+
+function phorum_htmlpurifier_migrate_sigs_check()
+{
+    global $PHORUM;
+    $offset = 0;
+    if (!empty($_POST['migrate-sigs'])) {
+        if (!isset($_POST['confirmation']) || strtolower($_POST['confirmation']) !== 'yes') {
+            echo 'Invalid confirmation code.';
+            exit;
+        }
+        $PHORUM['mod_htmlpurifier']['migrate-sigs'] = true;
+        phorum_db_update_settings(array("mod_htmlpurifier"=>$PHORUM["mod_htmlpurifier"]));
+        $offset = 1;
+    } elseif (!empty($_GET['migrate-sigs']) && $PHORUM['mod_htmlpurifier']['migrate-sigs']) {
+        $offset = (int) $_GET['migrate-sigs'];
+    }
+    return $offset;
+}
+
+function phorum_htmlpurifier_migrate_sigs($offset)
+{
+    global $PHORUM;
+
+    if(!$offset) return; // bail out quick if $offset == 0
+
+    // theoretically, we could get rid of this multi-request
+    // doo-hickery if safe mode is off
+    @set_time_limit(0); // attempt to let this run
+    $increment = $PHORUM['mod_htmlpurifier']['migrate-sigs-increment'];
+
+    require_once(dirname(__FILE__) . '/../migrate.php');
+    // migrate signatures
+    // do this in batches so we don't run out of time/space
+    $end = $offset + $increment;
+    $user_ids = array();
+    for ($i = $offset; $i < $end; $i++) {
+        $user_ids[] = $i;
+    }
+    $userinfos = phorum_db_user_get_fields($user_ids, 'signature');
+    foreach ($userinfos as $i => $user) {
+        if (empty($user['signature'])) continue;
+        $sig = $user['signature'];
+        // perform standard Phorum processing on the sig
+        $sig = str_replace(array("&","<",">"), array("&amp;","&lt;","&gt;"), $sig);
+        $sig = preg_replace("/<((http|https|ftp):\/\/[a-z0-9;\/\?:@=\&\$\-_\.\+!*'\(\),~%]+?)>/i", "$1", $sig);
+        // prepare fake data to pass to migration function
+        $fake_data = array(array("author"=>"", "email"=>"", "subject"=>"", 'body' => $sig));
+        list($fake_message) = phorum_htmlpurifier_migrate($fake_data);
+        $user['signature'] = $fake_message['body'];
+        if (!phorum_api_user_save($user)) {
+            exit('Error while saving user data');
+        }
+    }
+    unset($userinfos); // free up memory
+
+    // query for highest ID in database
+    $type = $PHORUM['DBCONFIG']['type'];
+    $sql = "select MAX(user_id) from {$PHORUM['user_table']}";
+    $row = phorum_db_interact(DB_RETURN_ROW, $sql);
+    $top_id = (int) $row[0];
+
+    $offset += $increment;
+    if ($offset > $top_id) { // test for end condition
+        echo 'Migration finished';
+        $PHORUM['mod_htmlpurifier']['migrate-sigs'] = false;
+        phorum_htmlpurifier_commit_settings();
+        return true;
+    }
+    $host  = $_SERVER['HTTP_HOST'];
+    $uri   = rtrim(dirname($_SERVER['PHP_SELF']), '/\\');
+    $extra = 'admin.php?module=modsettings&mod=htmlpurifier&migrate-sigs=' . $offset;
+    // relies on output buffering to work
+    header("Location: http://$host$uri/$extra");
+    exit;
+
+}
+
+// vim: et sw=4 sts=4