Remove files that have already been ported or do not need to be ported.

client/html/src/Node.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.
-
-// TODO(jacobr): stop extending eventTarget.
-interface Node extends EventTarget {
-
-  NodeList get nodes();
-
-  void set nodes(Collection<Node> value);
-
-  Node get nextNode();
-
-  Document get document();
-
-  Node get parent();
-
-  Node get previousNode();
-
-  String get text();
-
-  void set text(String value);
-
-  Node replaceWith(Node otherNode);
-
-  Node remove();
-
-  bool contains(Node otherNode);
-
-  // TODO(jacobr): remove when/if Array supports a method similar to
-  // insertBefore or we switch NodeList to implement LinkedList rather than
-  // array.
-  Node insertBefore(Node newChild, Node refChild);
-
-  Node clone(bool deep);
-}