Refactor fn2.dart, since it breached our 1000-line threshold.

sky/examples/widgets/hello_widgets.dart

Index: sky/examples/widgets/hello_widgets.dart
diff --git a/sky/examples/fn2/hello_fn2.dart b/sky/examples/widgets/hello_widgets.dart
similarity index 84%
rename from sky/examples/fn2/hello_fn2.dart
rename to sky/examples/widgets/hello_widgets.dart
index 1aeda5d2ebc12d0dc5ab9d17586b64f0e99118af..127e26fa9e749708ea411180523440a8c3909fc5 100644
--- a/sky/examples/fn2/hello_fn2.dart
+++ b/sky/examples/widgets/hello_widgets.dart
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'package:sky/framework/fn2.dart';
+import 'package:sky/framework/widgets/wrappers.dart';
 
 class HelloWorldApp extends App {
   UINode build() {
@@ -12,4 +12,4 @@ class HelloWorldApp extends App {
 
 void main() {
   new HelloWorldApp();
-}
+}