Joystick stuffs!

Changed the interface somewhat because I'm allergic to dynamic memory allocations. Hope you're fine with that :P Tested on Debian with my 360 controller :D

I also went ahead and made the JOYSTICK_X enums strongly-typed. I like IDs/handles that can't be confused with other types. It currently stands out from the rest of the API somewhat, but if you care, the other enums could be changed to this pattern as well. Unless you don't like it, in which case, just nuke my change :P