Rationalize Dart mojo and sky package structure

sky/framework/components/popup_menu_item.dart

Index: sky/framework/components/popup_menu_item.dart
diff --git a/sky/framework/components/popup_menu_item.dart b/sky/framework/components/popup_menu_item.dart
deleted file mode 100644
index e610be69a1d8bd5478e9964a8eb9f8de67172dc4..0000000000000000000000000000000000000000
--- a/sky/framework/components/popup_menu_item.dart
+++ /dev/null
@@ -1,26 +0,0 @@
-// 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 '../fn.dart';
-import 'ink_well.dart';
-
-class PopupMenuItem extends Component {
-  static final Style _style = new Style('''
-    min-width: 112px;
-    padding: 16px;''');
-
-  List<UINode> children;
-  double opacity;
-
-  PopupMenuItem({ Object key, this.children, this.opacity}) : super(key: key);
-
-  UINode build() {
-    return new StyleNode(
-      new InkWell(
-        inlineStyle: opacity == null ? null : 'opacity: ${opacity}',
-        children: children
-      ),
-      _style);
-  }
-}