Restructure pkg/unittest and pkg/webdriver to follow the pub conventions.

pkg/intl/test/date_time_format_test_core.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.
 
 /**
  * Tests the DateFormat library in dart. This file contains core tests that
  * are run regardless of where the locale data is found, so it doesn't expect to
  * be run on its own, but rather to be imported and run from another test file.
  */
 
 library date_time_format_tests;
 
-import '../../../pkg/unittest/unittest.dart';
+import '../../../pkg/unittest/lib/unittest.dart';
 import 'date_time_format_test_data.dart';
 import '../lib/intl.dart';
 import '../lib/src/date_format_internal.dart';
 
 var formatsToTest = const [
   DateFormat.DAY,
   DateFormat.ABBR_WEEKDAY,
   DateFormat.WEEKDAY,
   DateFormat.ABBR_STANDALONE_MONTH,
   DateFormat.STANDALONE_MONTH,
@@ skipping 315 matching lines @@
 
   test('Test default format', () {
     var someDate = new Date(2012, 1, 27, 20, 58, 59, 1);
     var emptyFormat = new DateFormat(null, "en_US");
     var knownDefault = new DateFormat.yMMMMd("en_US").add_jms();
     var result = emptyFormat.format(someDate);
     var knownResult = knownDefault.format(someDate);
     expect(result, knownResult);
   });
 }