Add date formatting and parsing code.

tests/lib/i18n/intl_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_test');
+
+#import('../../../lib/i18n/intl.dart');
+#import('../../../lib/unittest/unittest.dart');
+
+main() {
+  test('Set locale', (){
+    var de = new Intl('de_DE');
+    expect(de.locale, equals('de_DE'));
+  });
+}