MDL-9151 HTML Purifier cleaning support - enable switch is in experimental section

MDL-9435 Reviewved url cleaning in redirect()

lib/htmlpurifier/HTMLPurifier/AttrDef/URI/Email.php

@@ -0,0 +1,17 @@
+<?php
+
+require_once 'HTMLPurifier/AttrDef.php';
+
+class HTMLPurifier_AttrDef_URI_Email extends HTMLPurifier_AttrDef
+{
+    
+    /**
+     * Unpacks a mailbox into its display-name and address
+     */
+    function unpack($string) {
+        // needs to be implemented
+    }
+    
+}
+
+?>