Adding URIScheme filter for #98

lib/Haanga/lib/Haanga/Extension/Filter/Urischeme.php

+<?php
+
+class Haanga_Extension_Filter_Urischeme
+{
+    static function generator($cmp, $args)
+    {
+        return hexec('parse_url', $args[0], hconst('PHP_URL_SCHEME'));
+    }
+}