Moved all OpenGL classes to their own package.

I'm about to do THE single most club-headded thing ever: Turn OpenGL's enums into actual enums. I can't stand this undocumented crap.
This will suck up memory like no one's business, but we're talking, what, 1 KB per enum?
It would also go blazingly fast if Java's enum system weren't the piece of crap it is atm.
On the bright side, I also plan on making a GLContext interface, for easy switching from LWJGL to JOGL. So there's that.