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

tests/html/xmldocument_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('XMLDocumentTest');
-#import('../../pkg/unittest/unittest.dart');
-#import('../../pkg/unittest/html_config.dart');
-#import('dart:html');
+library XMLDocumentTest;
+import '../../pkg/unittest/lib/unittest.dart';
+import '../../pkg/unittest/lib/html_config.dart';
+import 'dart:html';
 
 main() {
   useHtmlConfiguration();
 
   var isXMLDocument = predicate((x) => x is XMLDocument, 'is an XMLDocument');
   var isXMLElement = predicate((x) => x is XMLElement, 'is an XMLElement');
 
   XMLDocument makeDocument() => new XMLDocument.xml("<xml><foo/><bar/></xml>");
 
   group('constructor', () {
@@ skipping 592 matching lines @@
     test('manifest', () => expect(makeDocument().manifest), '');
   });
 
   test('unsupported operations', () {
     expectUnsupported(() { makeDocument().body = new XMLElement.tag('xml'); });
     expectUnsupported(() => makeDocument().cookie);
     expectUnsupported(() { makeDocument().cookie = 'foo'; });
     expectUnsupported(() { makeDocument().manifest = 'foo'; });
   });
 }