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

tests/html/typed_arrays_arraybuffer_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('typed_arrays_arraybuffer_test');
-#import('../../pkg/unittest/unittest.dart');
-#import('../../pkg/unittest/html_config.dart');
-#import('dart:html');
+library typed_arrays_arraybuffer_test;
+import '../../pkg/unittest/lib/unittest.dart';
+import '../../pkg/unittest/lib/html_config.dart';
+import 'dart:html';
 
 main() {
   useHtmlConfiguration();
 
   test('constructor', () {
       var a = new ArrayBuffer(100);
       expect(a.byteLength, 100);
   });
 
   test('slice1', () {
@@ skipping 13 matching lines @@
       var s = a.slice(50, 10);
       expect(s.byteLength, 0);   // end before start becomes empty range.
   });
 
   test('slice4', () {
       var a = new ArrayBuffer(100);
       var s = a.slice(-90, -30);
       expect(s.byteLength, 60);  // negative indexes measure from end.
   });
 }