Add UNL_Auth and SimpleCAS packages to lib

lib/php/SimpleCAS/ProxyGranting/Storage.php

+<?php
+interface SimpleCAS_ProxyGranting_Storage
+{
+    function saveIOU($iou);
+    function getProxyGrantingTicket($iou);
+}
+?>
\ No newline at end of file

lib/php/SimpleCAS/ProxyGranting/Storage/File.php

+<?php
+class SimpleCAS_ProxyGranting_Storage_File implements SimpleCAS_ProxyGranting_Storage
+{
+    function saveIOU($iou)
+    {
+        throw new Exception('not implemented');
+    }
+    
+    function getProxyGrantingTicket($iou)
+    {
+        throw new Exception('not implemented');
+    }
+}
+?>
\ No newline at end of file