Win32: Switch to RawInput for keyboard processing. Lets us distinguish LSHIFT/RSHIFT and LCTRL/RCTRL.
Use EXT_swap_control_tear when available to ensure that VSync never slows things down (tears instead if it can't keep up, better than stuttering)
Fix bug with unthrottle as virtual key. Add button to restore default key mappings.
Let the user map unthrottle and rapidfire. Make more keys mappable.