Update unittest to new package layout.

tests/html/element_constructor_1_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.
 
 // Put universally passing event constructors in this file.
 // Move constructors that fail on some configuration to their own
 // element_constructor_foo_test.dart file.
 
 #library('ElementConstructorTest');
-#import('../../pkg/unittest/unittest.dart');
-#import('../../pkg/unittest/html_config.dart');
+#import('../../pkg/unittest/lib/unittest.dart');
+#import('../../pkg/unittest/lib/html_config.dart');
 #import('dart:html');
 
 main() {
   useHtmlConfiguration();
 
   test('anchor1', () {
       var e = new AnchorElement();
       Expect.isTrue(e is AnchorElement);
     });
 
@@ skipping 35 matching lines @@
   test('span', () {
       var e = new SpanElement();
       Expect.isTrue(e is SpanElement);
     });
 
   test('select', () {
       var e = new SelectElement();
       Expect.isTrue(e is SelectElement);
     });
 }