Roll Observatory packages and add a roll script

packages/initialize/lib/initialize.dart

 // Copyright (c) 2015, 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 initialize;
 
 // The `loader_replacer` transformer will replace this with a static_loader.
 import 'src/mirror_loader.dart' as loader;
 import 'dart:async';
 import 'dart:collection';
 
@@ skipping 19 matching lines @@
 
 Future _runInitQueue(Queue<Function> initializers) {
   if (initializers.isEmpty) return new Future.value(null);
 
   var initializer = initializers.removeFirst();
   var val = initializer();
   if (val is! Future) val = new Future.value(val);
 
   return val.then((_) => _runInitQueue(initializers));
 }