Core
* Add automatic tests.
* Make libuv loop pause in nested message loop (like a call to "alert()").
* Add 'plugins' dir in app to plugin search path.
* Fix crashes caused by creating V8 handles without handle scope.
* Expose window object to Node's context.
* The 'node-main' script should executes before window context is created.

Devtools
* Force closing previous debug session.

Mac
* Improve message loop's performance and stability.
* Fix crash when dragging images.

Windows
* Fix crash on Windows XP.