Add new GamepadButton enum with bits corresponding to AppleJack button bits.
Both the AppleJack controller and the SDL GameController coincidentally define
one d-pad, two shoulder buttons, four face buttons, and three system buttons.
This makes mapping modern game controllers to the AppleJack straightforward.
Add absolute coordinates for tablets. Absolute coordinates is relative to window so it can't work for multiple displays? Doesn't work for single display without mouse driver modification.
Add arbitrary number of buttons. Previously, only one mouse button was supported.
Add arbitrary number of bits. Previously, only 7 bits per axis was supported which is good enough for relative movement but not absolute movement.
There are cases where when it's necessary (e.g. given uninitialized NVRAM,
the Beige G3 with the 10.2 install CD inserted will update the boot
device and restart to boot from it).
Restart support was done by wrapping the ppc_exec function in a loop and
checking for a restart power off reason. We also need to disconnect all
event listeners, since they will be recreated when the machine is
re-initialized.