isolates refactor: this change introduces 'dart:isolate' as a library. This is a

samples/proxy/promise.dart

 // Copyright (c) 2012, 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.
 
 /** A library to illustrate pipelining. */
 #library("promise");
+#import("dart:isolate");
 
 /** A promise to value of type [T] that may be computed asynchronously. */
 // TODO(sigmund,benl): remove Promise<T> use Future<T> instead.
 interface Promise<T> default PromiseImpl<T> {
 
   Promise();
 
   /** A promise that already has a computed value. */
   Promise.fromValue(T value);
 
@@ skipping 529 matching lines @@
         } 
       }
       return process(marshalled);
     }).flatten();
   }
 
   Promise<SendPort> _promise;
   static Map<SendPort, Dispatcher> _dispatchers;
 
 }