Move unittest from lib to pkg.

tests/html/node_test.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.
 
 #library('NodeTest');
-#import('../../lib/unittest/unittest.dart');
-#import('../../lib/unittest/html_config.dart');
+#import('../../pkg/unittest/unittest.dart');
+#import('../../pkg/unittest/html_config.dart');
 #import('dart:html');
 
 Node makeNode() => new Element.tag('div');
 Node makeNodeWithChildren() =>
   new Element.html("<div>Foo<br/><!--baz--></div>");
 
 main() {
   useHtmlConfiguration();
 
   test('replaceWith', () {
@@ skipping 169 matching lines @@
     });
 
     test('getRange', () {
       var range = makeNodeList().getRange(1, 2);
       Expect.isTrue(range is NodeList);
       Expect.isTrue(range[0] is BRElement);
       Expect.isTrue(range[1] is Comment);
     });
   });
 }