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/ConfigSchema/Interchange/Directive.php

@@ -0,0 +1,89 @@
+<?php
+
+/**
+ * Interchange component class describing configuration directives.
+ */
+class HTMLPurifier_ConfigSchema_Interchange_Directive
+{
+
+    /**
+     * ID of directive.
+     * @type HTMLPurifier_ConfigSchema_Interchange_Id
+     */
+    public $id;
+
+    /**
+     * Type, e.g. 'integer' or 'istring'.
+     * @type string
+     */
+    public $type;
+
+    /**
+     * Default value, e.g. 3 or 'DefaultVal'.
+     * @type mixed
+     */
+    public $default;
+
+    /**
+     * HTML description.
+     * @type string
+     */
+    public $description;
+
+    /**
+     * Whether or not null is allowed as a value.
+     * @type bool
+     */
+    public $typeAllowsNull = false;
+
+    /**
+     * Lookup table of allowed scalar values.
+     * e.g. array('allowed' => true).
+     * Null if all values are allowed.
+     * @type array
+     */
+    public $allowed;
+
+    /**
+     * List of aliases for the directive.
+     * e.g. array(new HTMLPurifier_ConfigSchema_Interchange_Id('Ns', 'Dir'))).
+     * @type HTMLPurifier_ConfigSchema_Interchange_Id[]
+     */
+    public $aliases = array();
+
+    /**
+     * Hash of value aliases, e.g. array('alt' => 'real'). Null if value
+     * aliasing is disabled (necessary for non-scalar types).
+     * @type array
+     */
+    public $valueAliases;
+
+    /**
+     * Version of HTML Purifier the directive was introduced, e.g. '1.3.1'.
+     * Null if the directive has always existed.
+     * @type string
+     */
+    public $version;
+
+    /**
+     * ID of directive that supercedes this old directive.
+     * Null if not deprecated.
+     * @type HTMLPurifier_ConfigSchema_Interchange_Id
+     */
+    public $deprecatedUse;
+
+    /**
+     * Version of HTML Purifier this directive was deprecated. Null if not
+     * deprecated.
+     * @type string
+     */
+    public $deprecatedVersion;
+
+    /**
+     * List of external projects this directive depends on, e.g. array('CSSTidy').
+     * @type array
+     */
+    public $external = array();
+}
+
+// vim: et sw=4 sts=4