Move example fn widgets into sky/framework/components

sky/framework/components/floating_action_button.dart

-part of widgets;
+// 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.
 
-class FloatingActionButton extends MaterialComponent {
+import '../fn.dart';
+import 'material.dart';
+import '../theme/colors.dart';
+import '../theme/shadows.dart';
+
+class FloatingActionButton extends Material {
   static final Style _style = new Style('''
     position: absolute;
     bottom: 16px;
     right: 16px;
     z-index: 5;
     transform: translateX(0);
     width: 56px;
     height: 56px;
     background-color: ${Red[500]};
     color: white;
@@ skipping 28 matching lines @@
       children: [
         new Container(
           key: "Clip",
           style: _clipStyle,
           children: children
         )
       ]
     );
   }
 }