Add appengine/gcloud/mustache dependencies.

pkg/gcloud/lib/db/metamodel.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.
+
+library gcloud.db.meta_model;
+
+import '../db.dart' as db;
+
+@db.Kind(name: '__namespace__')
+class Namespace extends db.ExpandoModel {
+  static const int EmptyNamespaceId = 1;
+
+  String get name {
+    // The default namespace will be reported with id 1.
+    if (id == Namespace.EmptyNamespaceId) return null;
+    return id;
+  }
+}
+
+@db.Kind(name: '__kind__')
+class Kind extends db.Model {
+  String get name => id;
+}