Roll Observatory packages and add a roll script

packages/template_binding/lib/src/node.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.
 
 part of template_binding;
 
 /** Extensions to the [Node] API. */
 class NodeBindExtension {
   final Node _node;
   final JsObject _js;
@@ skipping 180 matching lines @@
    */
   Node get lastNode => _lastNode;
 
   /** The model used to instantiate the template. */
   final model;
 
   Node _firstNode, _lastNode;
 
   TemplateInstance(this.model);
 }