Restructure pkg/unittest and pkg/webdriver to follow the pub conventions.

tests/html/window_mangling_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('WindowManglingTest');
-#import('../../pkg/unittest/unittest.dart');
-#import('../../pkg/unittest/html_config.dart');
-#import('dart:html', prefix: 'dom');
+library WindowManglingTest;
+import '../../pkg/unittest/lib/unittest.dart';
+import '../../pkg/unittest/lib/html_config.dart';
+import 'dart:html' as dom;
 
 // Defined in dom.Window.
 get navigator => "Dummy";
 
 $eq(x, y) => false;
 $eq$(x, y) => false;
 
 main() {
   useHtmlConfiguration();
   var win = dom.window;
 
   test('windowMethod', () {
       final message = navigator;
       final x = win.navigator;
       expect(x, isNot(equals(message)));
     });
 
   test('windowEquals', () {
       expect($eq(win, win), isFalse);
       expect(win == win, isTrue);
     });
 
   test('windowEquals', () {
       expect($eq$(win, win), isFalse);
       expect(win == win, isTrue);
     });
 }