[API] Load bundles from imperative registry

src/BundleRegistry.js

@@ -22,6 +22,8 @@
 /*global define*/
 
 define(function () {
+    'use strict';
+
     function BundleRegistry() {
         this.bundles = {};
     }
@@ -38,5 +40,9 @@ define(function () {
         return this.bundles[path];
     };
 
+    BundleRegistry.prototype.list = function () {
+        return Object.keys(this.bundles);
+    };
+
     return BundleRegistry;
 });