Date formatting again with fixes

tests/lib/i18n/intl_message_test.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.
 
 
 #library('intl_message_test');
 
 #import('../../../lib/i18n/intl.dart');
 #import('../../../lib/unittest/unittest.dart');
 
@@ skipping 63 matching lines @@
 
   test('WithLocale test', () {
     hello() => Intl.message('locale=${Intl.getCurrentLocale()}',
         desc: 'explains the locale');
     expect(Intl.withLocale('en-US', () => hello()), equals('locale=en-US'));
   });
 
   test('Test passing locale', () {
     hello(a_locale) => Intl.message('locale=${Intl.getCurrentLocale()}',
         desc: 'explains the locale', locale: a_locale);
-    expect(hello('en-US'), equals('locale=en-US'));
+    expect(hello('en-US'), equals('locale=en_US'));
   });
 }