Add unittest to apidoc and fix readme.

lib/unittest/unittest.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.
 
 /**
  * A library for writing dart unit tests.
  *
+ * To import this library, specify the relative path to lib/unittest.dart.

[Siggi Cherem (dart-lang), 2012/05/18 23:33:32]

lib/unittest.dart => lib/unittest/unittest.dart

+ *
  * ##Concepts##
  *
  *  * Tests: Tests are specified via the top-level function [test], they can be
  *    organized together using [group].
  *  * Checks: Test expectations can be specified via [expect] (see methods in
  *    [Expectation]), [expectThrow], or using assertions with the [Expect]
  *    class.
  *  * Configuration: The framework can be adapted by calling [configure] with a
  *    [Configuration].  Common configurations can be found in this package
  *    under: 'dom\_config.dart', 'html\_config.dart', and 'vm\_config.dart'.
@@ skipping 67 matching lines @@
  *         }, count: 2); // <-- we can indicate multiplicity to [expectAsync0]
  *         window.setTimeout(callback, 0);
  *         window.setTimeout(callback, 0);
  *       });
  *     }
  *
  * Note: due to some language limitations we have to use different functions
  * depending on the number of positional arguments of the callback. In the
  * future, we plan to expose a single `expectAsync` function that can be used
  * regardless of the number of positional arguments. This requires new langauge
  * features or fixes to the current spec (e.g. see dartbug.com/2706).

[Siggi Cherem (dart-lang), 2012/05/18 23:33:32]

let's make this url a link. 

  *
  * Meanwhile, we plan to add this alternative API for callbacks of more than 2
  * arguments or that take named parameters. (this is not implemented yet,
  * but will be coming here soon).
  *
  *     #import('path-to-dart/lib/unittest/unitest.dart');
  *     #import('dart:dom_deprecated');
  *     main() {
  *       test('calllback is executed', () {
  *         // indicate ahead of time that an async callback is expected.
@@ skipping 461 matching lines @@
   }
   _config.onInit();
 
   // Immediately queue the suite up. It will run after a timeout (i.e. after
   // main() has returned).
   _defer(_runTests);
 }
 
 /** Signature for a test function. */
 typedef void TestFunction();