Commit initial URI unit tests and implementation. They're not complete yet though.

git-svn-id: http://htmlpurifier.org/svnroot/htmlpurifier/trunk@206 48356398-32a2-884e-a903-53898d9a118a

library/HTMLPurifier/URISchemeRegistry.php

@@ -0,0 +1,23 @@
+<?php
+
+class HTMLPurifier_URISchemeRegistry
+{
+    
+    // pass a registry object $prototype with a compatible interface and
+    // the function will copy it and return it all further times.
+    // pass bool true to reset to the default registry
+    function &instance($prototype = null) {
+        static $instance = null;
+        if ($prototype !== null) {
+            $instance = $prototype;
+        } elseif ($instance === null || $prototype == true) {
+            $instance = new HTMLPurifier_URISchemeRegistry();
+        }
+        return $instance;
+    }
+    
+    function &getScheme($scheme) {}
+    
+}
+
+?>