unittest step2: bye bye to multiple entrypoints for unittest

samples/tests/samples/src/lib/util/UtilTest.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('util_tests');
 
 #import('dart:html');
-#import('../../../../../../lib/unittest/unittest_html.dart');
+#import('../../../../../../lib/unittest/unittest.dart');
+#import('../../../../../../lib/unittest/html_config.dart');
 #import('../../../../../ui_lib/util/utilslib.dart');
 
 main() {
+  useHtmlConfiguration();
   test('insertAt', () {
     var a = [];
     CollectionUtils.insertAt(a, 0, 1);
     expect(a).equalsCollection([1]);
 
     CollectionUtils.insertAt(a, 0, 2);
     expect(a).equalsCollection([2, 1]);
 
     CollectionUtils.insertAt(a, 0, 5);
     CollectionUtils.insertAt(a, 0, 4);
@@ skipping 12 matching lines @@
     CollectionUtils.insertAt(a, 3, 5);
     expect(a).equalsCollection([1, 3, 2, 5, 4]);
   });
 
   test('defaultString', () {
     expect(StringUtils.defaultString(null)).equals('');
     expect(StringUtils.defaultString('')).equals('');
     expect(StringUtils.defaultString('test')).equals('test');
   });
 }