webui fixes for 0.8.9

lib/templating.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /** Common utility functions used by code generated by the dwc compiler. */
 library templating;
 
 import 'dart:async';
-import 'dart:collection';
 import 'dart:html';
-import 'dart:svg' as svg;
 import 'package:web_ui/safe_html.dart';
 import 'package:web_ui/observe.dart';
 import 'package:web_ui/watcher.dart';
 import 'package:web_ui/web_ui.dart' show WebComponent;
 
 /**
  * Empty sanitizer used to create HTML content that was already sanitized during
  * compilation.
  */
 NodeTreeSanitizer nullTreeSanitizer = new _NullTreeSanitizer();
@@ skipping 655 matching lines @@
     node.nodes.clear();
     nodes.clear();
   }
 
   void remove() {
     _removeInternal();
     stopper();
     stopper = null;
   }
 }