Rename UINode to Widget.

sky/examples/raw/navigation.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/widgets/basic.dart';
-import 'package:sky/widgets/navigator.dart';
-import 'package:sky/widgets/raised_button.dart';
-
-List<Route> routes = [
-  new Route(
-    name: 'safety',
-    builder: (navigator) => new RaisedButton(
-      child: new Text('PRESS FORWARD'),
-      onPressed: () => navigator.pushNamedRoute('adventure')
-    )
-  ),
-  new Route(
-    name: 'adventure',
-    builder: (navigator) => new RaisedButton(
-      child: new Text('NO WAIT! GO BACK!'),
-      onPressed: () => navigator.pushRoute(routes[0])
-    )
-  )
-];
-
-class NavigationExampleApp extends App {
-  UINode build() {
-    return new Navigator(routes: routes);
-  }
-}
-
-void main() {
-  App app = new NavigationExampleApp();
-}