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

pkg/unittest/lib/expect.dart

Index: pkg/unittest/lib/expect.dart
===================================================================
--- pkg/unittest/lib/expect.dart	(revision 0)
+++ pkg/unittest/lib/expect.dart	(working copy)
@@ -2,9 +2,23 @@
 // 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.
 
-part of unittest;
+part of matcher;
 
 /**
+ * Some matchers, like those for Futures and exception testing,
+ * can fail in asynchronous sections, and throw exceptions.
+ * A user of this library will typically want to catch and handle 
+ * such exceptions. The [asyncGuard] property is a function that

[Siggi Cherem (dart-lang), 2012/10/31 20:54:02]

asyncGuard => _wrapAsync?

[gram, 2012/11/01 21:23:19]

Done.

+ * can wrap callbacks used by these Matchers so that they can be
+ * used safely. For example, the unittest library will set this
+ * to be expectAsync1. By default this is an identity function.
+ */

[Siggi Cherem (dart-lang), 2012/10/31 20:54:02]

nits:
- move this comment to the publicly visible property so that it gets included in
this library's documentation.
- remove empty line after this block

[gram, 2012/11/01 21:23:19]

Done.

+
+Function _wrapAsync = (f) => f;
+
+set wrapAsync(Function f) => _wrapAsync = f;

[Siggi Cherem (dart-lang), 2012/10/31 20:54:02]

seems silly to have a private property that can be publicly set and not written,
maybe simply combine the two and make this a public field?

[gram, 2012/11/01 21:23:19]

Done.

+
+/**
  * This is the main assertion function. It asserts that [actual]
  * matches the [matcher]. [reason] is optional and is typically not
  * supplied, as a reason is generated from the matcher; if [reason]