Roll Observatory packages and add a roll script

packages/observe/lib/transformer.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.
 
 /// Code transform for @observable. The core transformation is relatively
 /// straightforward, and essentially like an editor refactoring.
 library observe.transformer;
 
 import 'dart:async';
 
@@ skipping 396 matching lines @@
     token = token.next;
   }
   return token;
 }
 
 // TODO(sigmund): remove hard coded Polymer support (@published). The proper way
 // to do this would be to switch to use the analyzer to resolve whether
 // annotations are subtypes of ObservableProperty.
 final observableMatcher =
     new RegExp("@(published|observable|PublishedProperty|ObservableProperty)");