BIG CHANGES!

Big changes and two revisions here! First, guitar controllers should
work! I don't have one to test, but the code is there. You will have to
re-map the controller though. I'll try to map them both. Second,
PS2-USB is PS3 compatible(ish)! All the buttons and axes work,
including the D-Pad (which was changed to a POV hat for compatibility)!
Currently, the PS button is not supported, but I'm working on that now.
Lastly, I've included working EAGLE schematics! I have tested these and
they work. I also included a modified teensy EAGLE part that I used,
based on Mark Gross's.