Add the floating action button to stocks2

sky/examples/stocks2/lib/stock_app.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/components2/tool_bar.dart';
 import 'package:sky/framework/components2/drawer.dart';
 // import 'package:sky/framework/components2/drawer_header.dart';
-// import 'package:sky/framework/components2/floating_action_button.dart';
-// import 'package:sky/framework/components2/icon.dart';
+import 'package:sky/framework/components2/floating_action_button.dart';
+import 'package:sky/framework/components2/icon.dart';
 import 'package:sky/framework/components2/icon_button.dart';
 import 'package:sky/framework/components2/menu_divider.dart';
 import 'package:sky/framework/components2/menu_item.dart';
 import 'package:sky/framework/components2/input.dart';
 // import 'package:sky/framework/components2/modal_overlay.dart';
 // import 'package:sky/framework/components2/popup_menu.dart';
 import 'package:sky/framework/components2/radio.dart';
 import 'package:sky/framework/components2/scaffold.dart';
 import 'package:sky/framework/fn2.dart';
 import 'package:sky/framework/theme2/typography.dart' as typography;
@@ skipping 176 matching lines @@
     //     onAutorefreshChanged: _handleAutorefreshChanged
     //   )],
     //   onDismiss: _handleMenuHide));
   }
 
   UINode build() {
     List<UINode> overlays = [
       new Scaffold(
         toolbar: _isSearching ? buildSearchBar() : buildToolBar(),
         body: new Stocklist(stocks: _stocks, query: _searchQuery),
-        // floatingActionButton: new FloatingActionButton(
-        //   content: new Icon(type: 'content/add_white', size: 24),
-        //   level: 3),
+        floatingActionButton: new FloatingActionButton(
+          content: new Icon(type: 'content/add_white', size: 24),
+          level: 3),
         drawer: _drawerShowing ? buildDrawer() : null
       ),
     ];
     addMenuToOverlays(overlays);
     return new StackContainer(children: overlays);
   }
 }
 
 void main() {
   print("starting stocks app!");
   App app = new StocksApp();
   app.appView.onFrame = () {
     // uncomment this for debugging:
     // app.appView.debugDumpRenderTree();
   };
 }