Add possibility to provide different output locations for the Zencoder API.

Hi all.
I've been quickly hacking together a prototype so it's possible to add different output locations for the Zencoder API.
What my patch does is: add a submodule which provides a hook so any module can provide an output location (eg. ftp://user:password@host/output_folder). Maybe that's a bit far fetched, but i was trying to be as flexible as possible. Then it generates a form input for the location in the Zencoder settings, and provides an option to choose it as well.

I know it could use some refactoring, and now that i think of it, it doesn't delete the output variable when it's deleted/input = empty.
And then there's the problem that maybe not all output locations are accessible, so the video can't be played ;)
But like i said, i'm just 'putting it out there' to get some feedback.
Thanx.