Enabled CSS tests, added CSS tests to buildbot, fixed tooling with nodejs, and added more tests.

utils/css/cssworld.dart

 // Copyright (c) 2011, 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.
 
 class CssWorld {
   List<String> classes;
   List<String> ids;
 
   CssWorld(this.classes, this.ids) {
     // Insure no private class names in our CSS world (._foo).
-    for (var aClass in classes) {
+    for (final aClass in classes) {
       if (aClass.startsWith('_')) {
         throw new CssSelectorException(
             "private class ('_' prefix) not valid for CssWorld $aClass)");
       }
     }
 
     // Insure no private element ids in our CSS world (#_foo).
-    for (var id in ids) {
+    for (final id in ids) {
       if (id.startsWith('_')) {
         throw new CssSelectorException(
             "private id ('_' prefix) not valid for CssWorld $id)");
       }
     }
   }
 }