Old code would, by coincidence, map 1->16 to 1->16, then 17->32 to
1->32, leaving 1 and 17 on the same button number.
We still map 33->56 to 1->24, creating some overlap. But at least that's
because StepMania will have run out of buttons.
THIS PATCH WILL CHANGE THE CODES OF JOYSTICK BUTTONS 17 AND UP.
