use in-tree extjs

orun/extjs/app.html

@@ -2,8 +2,8 @@
 <head>
     <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
     <title>%s</title>
-    <script src="http://cdn.sencha.com/ext/gpl/4.2.1/ext-all.js"></script>
-    <link rel="stylesheet" href="http://cdn.sencha.com/ext/gpl/4.2.1/resources/ext-theme-classic/ext-theme-classic-all.css">
+    <script src="/ext_421/ext-all.js"></script>
+    <link rel="stylesheet" href="/ext_421/resources/ext-theme-%s/ext-theme-%s-all.css">
     <script>
     Ext.onReady(function () {
     	%s