Stack&Tile should be available through scripting

[pulkomandy]

​http://www.haiku-os.org/community/forum/stack_tile_scriptable

The idea exposed in this forum thread is to have a way to stack and tile windows using hey or a similar tool. This is a good idea, so I'm opening this ticket before we forget about it.

I think this could be integrated to the BWindow scripting interface. There is the problem of getting a "handle" to an S&T group from one app to another using hey, however (since hey can only target one app at a time).