Prepare pubspec/CHANGELOG for version 0.1.2

lib/service_scope.dart

 // Copyright (c) 2014, 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.
 
 /// This library enables one to create a service scope in which code can run.
 ///
 /// A service scope is an environment in which code runs. The environment is a
 /// [Zone] with added functionality. Code can be run inside a new service scope
 /// by using the `fork(callback)` method. This will call `callback` inside a new
 /// service scope and will keep the scope alive until the Future returned by the
@@ skipping 45 matching lines @@
 ///          // add it to the current service scope with key `#dbpool`.
 ///          // In addition we insert a on-scope-exit callback which will be
 ///          // called once the application is done.
 ///          var pool = new DBPool(connections: 10);
 ///          scope.register(#dbpool, pool, onScopeExit: () => pool.close());
 ///          return runApp();
 ///       }).then((_) {
 ///         print('Server application shut down cleanly');
 ///       });
 ///     }
+///
+/// As an example, the `package:appengine/appengine.dart` package runs request
+/// handlers inside a service scope, which has most `package:gcloud` services
+/// registered.
+///
+/// The core application code can then be independent of `package:appengine`
+/// and instead depend only on the services needed (e.g.
+/// `package:gcloud/storage.dart`) by using getters in the service library (e.g.
+/// the `storageService`) which are implemented with service scope lookups.
 library gcloud.service_scope;
 
 import 'dart:async';
 
 /// The Symbol used as index in the zone map for the service scope object.
 const Symbol _ServiceScopeKey = #_gcloud.service_scope;
 
 /// An empty service scope.
 ///
 /// New service scope can be created by calling [fork] on the empty
@@ skipping 188 matching lines @@
   }
 }
 
 class _RegisteredEntry {
   final Object key;
   final Object value;
   final Function scopeExitCallback;
 
   _RegisteredEntry(this.key, this.value, this.scopeExitCallback);
 }