Rationalize Dart mojo and sky package structure

sky/sdk/lib/framework/editing/editable_text.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 '../fn.dart';
 import '../theme/colors.dart';
 import 'dart:async';
 import 'editable_string.dart';
 
 class EditableText extends Component {
@@ skipping 70 matching lines @@
     }
 
     if (_showCursor)
       children.add(new Container(key: 'cursor', style: _cursorStyle));
 
     return new Paragraph(
       children: children
     );
   }
 }