Renaming unittest library names to all have package prefix names.

pkg/unittest/lib/mock.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.
 
 /**
  * A simple mocking/spy library.
  *
  * ## Installing ##
  *
  * Use [pub][] to install this package. Add the following to your `pubspec.yaml`
@@ skipping 104 matching lines @@
  * Spys created with Mock.spy do not have user-defined behavior;
  * they are simply proxies,  and thus will throw an exception if
  * you call [when]. They capture all calls in the log, so you can
  * do assertions on their history, such as:
  *
  *       spy.getLogs(callsTo('bar')).verify(happenedOnce);
  *
  * [pub]: http://pub.dartlang.org
  */
 
-library mock;
+library unittest.mock;
 
 import 'dart:mirrors';
 import 'dart:collection' show LinkedHashMap;
 
 import 'matcher.dart';
 
 /**
  * The error formatter for mocking is a bit different from the default one
  * for unit testing; instead of the third argument being a 'reason'
  * it is instead a [signature] describing the method signature filter
@@ skipping 1402 matching lines @@
       }
     }
   }
 
   /** Clear both logs and behavior. */
   void reset() {
     resetBehavior();
     clearLogs();
   }
 }