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

tests/html/query_test.dart

 // Copyright (c) 2011, 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('QueryTest');
-#import('../../pkg/unittest/unittest.dart');
-#import('../../pkg/unittest/html_config.dart');
-#import('dart:html');
+library QueryTest;
+import '../../pkg/unittest/lib/unittest.dart';
+import '../../pkg/unittest/lib/html_config.dart';
+import 'dart:html';
 
 main() {
   useHtmlConfiguration();
 
   final div = new DivElement();
   final canvas = new CanvasElement(width: 200, height: 200);
   canvas.id = 'testcanvas';
   final element =
       new Element.html("<div><br/><img/><input/><img/></div>");
   document.body.nodes.addAll([div, canvas,  element]);
@@ skipping 29 matching lines @@
       expect(l[0], isImageElement);
       expect(l[1], isImageElement);
       expect(l[0], isNot(equals(l[1])));
     });
 
   test('queryAll (None)', () {
       List l = queryAll('video');
       expect(l.isEmpty, isTrue);
     });
 }