The new code is based on timestamps, rather than delays. This eliminates the
need to update every timer in timer_process(), which cost a non-trivial amount
of CPU time on low-end machines.
This involved changes to every user of the timer code, so this change almost
certainly introduces bugs.
- Joystick type now selectable
- Added emulation of standard joysticks with up to 8 buttons
- Added emulation of Microsoft Sidewinder pads
- Host->emulated joystick button & axis mapping now configurable (only on Windows atm)
- Gameport registers now take 1us to access - helps Sidewinder drivers
