Update unittest to new package layout.

pkg/unittest/test/mock_regexp_negative_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('unittestTest');
-#import('../../../pkg/unittest/unittest.dart');
+#import('../../../pkg/unittest/lib/unittest.dart');
 
 main() {
   test('Mocking: RegExp CallMatcher bad', () {
-    var m = new Mock();           
-    m.when(callsTo(matches('^[A-Z]'))).          
-           alwaysThrow('Method names must start with lower case.');      
-    m.Test();         
+    var m = new Mock();
+    m.when(callsTo(matches('^[A-Z]'))).
+           alwaysThrow('Method names must start with lower case.');
+    m.Test();
   });
 }