Make the date formatting library visible in apidoc by merging it into Intl

pkg/intl/test/intl_message_basic_example_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.
 
 /**
  * Tests internationalization of messages using the basic example as a template.
  */
 #library('intl_message_test_2');
 
-#import('../lib/date_format.dart');
 #import('../lib/date_symbol_data_local.dart');
 #import('../lib/intl.dart');
 #import('../lib/message_lookup_local.dart');
 #import('../example/basic/basic_example.dart');
 #import('../../unittest/unittest.dart');
 
 List list;
 
 main() {
   list = [];
   setup(runAllTests, addToList);
 }
 
 addToList(x) {list.add(x);}
 
 runAllTests(_) {
   setup(runProgram, addToList);
   test('Verify basic example printing localized messages', () {
   expect(list[0], "Ran at 00:00:00 on Thursday, January 1, 1970");
   expect(list[1], "Ausgedruckt am 00:00:00 am Donnerstag, 1. Januar 1970.");
   expect(list[2], "วิ่ง 0:00:00 on วันพฤหัสบดี 1 มกราคม 1970.");
   });
 }