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/library/HTMLPurifier/DefinitionCacheFactory.php

@@ -0,0 +1,106 @@
+<?php
+
+/**
+ * Responsible for creating definition caches.
+ */
+class HTMLPurifier_DefinitionCacheFactory
+{
+    /**
+     * @type array
+     */
+    protected $caches = array('Serializer' => array());
+
+    /**
+     * @type array
+     */
+    protected $implementations = array();
+
+    /**
+     * @type HTMLPurifier_DefinitionCache_Decorator[]
+     */
+    protected $decorators = array();
+
+    /**
+     * Initialize default decorators
+     */
+    public function setup()
+    {
+        $this->addDecorator('Cleanup');
+    }
+
+    /**
+     * Retrieves an instance of global definition cache factory.
+     * @param HTMLPurifier_DefinitionCacheFactory $prototype
+     * @return HTMLPurifier_DefinitionCacheFactory
+     */
+    public static function instance($prototype = null)
+    {
+        static $instance;
+        if ($prototype !== null) {
+            $instance = $prototype;
+        } elseif ($instance === null || $prototype === true) {
+            $instance = new HTMLPurifier_DefinitionCacheFactory();
+            $instance->setup();
+        }
+        return $instance;
+    }
+
+    /**
+     * Registers a new definition cache object
+     * @param string $short Short name of cache object, for reference
+     * @param string $long Full class name of cache object, for construction
+     */
+    public function register($short, $long)
+    {
+        $this->implementations[$short] = $long;
+    }
+
+    /**
+     * Factory method that creates a cache object based on configuration
+     * @param string $type Name of definitions handled by cache
+     * @param HTMLPurifier_Config $config Config instance
+     * @return mixed
+     */
+    public function create($type, $config)
+    {
+        $method = $config->get('Cache.DefinitionImpl');
+        if ($method === null) {
+            return new HTMLPurifier_DefinitionCache_Null($type);
+        }
+        if (!empty($this->caches[$method][$type])) {
+            return $this->caches[$method][$type];
+        }
+        if (isset($this->implementations[$method]) &&
+            class_exists($class = $this->implementations[$method], false)) {
+            $cache = new $class($type);
+        } else {
+            if ($method != 'Serializer') {
+                trigger_error("Unrecognized DefinitionCache $method, using Serializer instead", E_USER_WARNING);
+            }
+            $cache = new HTMLPurifier_DefinitionCache_Serializer($type);
+        }
+        foreach ($this->decorators as $decorator) {
+            $new_cache = $decorator->decorate($cache);
+            // prevent infinite recursion in PHP 4
+            unset($cache);
+            $cache = $new_cache;
+        }
+        $this->caches[$method][$type] = $cache;
+        return $this->caches[$method][$type];
+    }
+
+    /**
+     * Registers a decorator to add to all new cache objects
+     * @param HTMLPurifier_DefinitionCache_Decorator|string $decorator An instance or the name of a decorator
+     */
+    public function addDecorator($decorator)
+    {
+        if (is_string($decorator)) {
+            $class = "HTMLPurifier_DefinitionCache_Decorator_$decorator";
+            $decorator = new $class;
+        }
+        $this->decorators[$decorator->name] = $decorator;
+    }
+}
+
+// vim: et sw=4 sts=4