Added HTMLPurifier (http://htmlpurifier.org/) Version 3.3.0

- can be used via html class like: 

        $clean_html = html::purify($html);

- using it now in eTemplate to remove malicious code from html:
  a) when displaying "formatted text"
  b) when "formatted text" get's input by the user

phpgwapi/inc/htmlpurifier/library/HTMLPurifier/HTMLModule/Hypertext.php

@@ -0,0 +1,31 @@
+<?php
+
+/**
+ * XHTML 1.1 Hypertext Module, defines hypertext links. Core Module.
+ */
+class HTMLPurifier_HTMLModule_Hypertext extends HTMLPurifier_HTMLModule
+{
+
+    public $name = 'Hypertext';
+
+    public function setup($config) {
+        $a = $this->addElement(
+            'a', 'Inline', 'Inline', 'Common',
+            array(
+                // 'accesskey' => 'Character',
+                // 'charset' => 'Charset',
+                'href' => 'URI',
+                // 'hreflang' => 'LanguageCode',
+                'rel' => new HTMLPurifier_AttrDef_HTML_LinkTypes('rel'),
+                'rev' => new HTMLPurifier_AttrDef_HTML_LinkTypes('rev'),
+                // 'tabindex' => 'Number',
+                // 'type' => 'ContentType',
+            )
+        );
+        $a->formatting = true;
+        $a->excludes = array('a' => true);
+    }
+
+}
+
+// vim: et sw=4 sts=4