Cleanup sky/sdk/examples

sky/sdk/example/old/stocks/lib/stock_menu.dart

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 import 'package:sky/framework/fn.dart';
 import 'package:sky/framework/layout.dart';
 import 'package:sky/framework/components/popup_menu.dart';
 import 'package:sky/framework/components/checkbox.dart';
 import 'package:sky/framework/theme/view_configuration.dart';
 
@@ skipping 24 matching lines @@
         items: [
           [new Text('Add stock')],
           [new Text('Remove stock')],
           [new ParentDataNode(new Text('Autorefresh'), _flex1), checkbox],
         ],
         level: 4),
         _style
     );
   }
 }