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

pkg/webdriver/lib/webdriver.dart

Index: pkg/webdriver/lib/webdriver.dart
===================================================================
--- pkg/webdriver/lib/webdriver.dart	(revision 0)
+++ pkg/webdriver/lib/webdriver.dart	(working copy)
@@ -1,10 +1,16 @@
-#library('webdriver');
+// 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 webdriver;
+
 #import('dart:json');
 #import('dart:uri');
 #import('dart:io');
 #import('dart:math');
-#source('base64decoder.dart');
 
+part 'src/base64decoder.dart';
+
 /**
  * WebDriver bindings for Dart.
  *