Feature transition3d

@jcoleman @abram
Hello guys!

Thanks for your work on notification banner.
I've changed it's behavior to something like banner notification built in iOS.
Video:
     http://www.youtube.com/watch?v=XDoUKR8co80

Can we have this functionality merged?
I've based by changes on @abram's customization.

So this is tested in all orientations on iPad 2 (iOS 6) & iPod Touch (iOS 6)

What do you think?
I like old implementation (Android-like Toast) too, so maybe we should add argument that selects mode?

Also, because it's not possible (as far as i know) to make a screenshot of statusBar, new banner mode should be used without coverStatusBar.

Anyway, i would like to hear back from you and polish this code, so it can be merged.
Cheers!