Reorganize mdv and observe packages

pkg/mdv/test/node_bindings_test.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library node_bindings_test;
 
 import 'dart:async';
 import 'dart:html';
-import 'package:mdv_observe/mdv_observe.dart';
+import 'package:mdv/mdv.dart' as mdv;
+import 'package:observe/observe.dart';
 import 'package:unittest/html_config.dart';
 import 'package:unittest/unittest.dart';
-import 'mdv_observe_utils.dart';
+import 'observe_utils.dart';
 
 // Note: this file ported from
 // https://github.com/toolkitchen/mdv/blob/master/tests/node_bindings.js
 
 main() {
+  mdv.initialize();
   useHtmlConfiguration();
   group('Node Bindings', nodeBindingTests);
 }
 
 sym(x) => new Symbol(x);
 
 nodeBindingTests() {
   var testDiv;
 
   setUp(() {
@@ skipping 119 matching lines @@
     expect(input.checked, false);
 
     input.click();
     expect(model[sym('x')], true);
     deliverChangeRecords();
 
     input.click();
     expect(model[sym('x')], false);
   });
 }