Allow Effen Styles to be extendable

sky/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 57 matching lines @@
     if (!value.composing.isValid) {
       children.add(new Text(value.text));
     } else {
       String beforeComposing = value.textBefore(value.composing);
       if (!beforeComposing.isEmpty)
         children.add(new Text(beforeComposing));
 
       String composing = value.textInside(value.composing);
       if (!composing.isEmpty) {
         children.add(new Container(
-          key: 'composing', 
-          styles: [_composingStyle],
+          key: 'composing',
+          style: _composingStyle,
           children: [new Text(composing)]
         ));
       }
 
       String afterComposing = value.textAfter(value.composing);
       if (!afterComposing.isEmpty)
         children.add(new Text(afterComposing));
     }
 
     if (_showCursor)
-      children.add(new Container(key: 'cursor', styles: [_cusorStyle]));
+      children.add(new Container(key: 'cursor', style: _cusorStyle));
 
     return new Container(
-      styles: [_style],
+      style: _style,
       children: children
     );
   }
 }