New pref to choose between Pov or Keys for D Pad, making it work
similarly to C Pad, C Stick and Touch.
Will automatically check whether vJoy has 4-way Pov or Continuous Pov
enabled and choose the correct one to output.
It all merged, it compiled and it works. There are 2 separate
implementations of POV switches in this which I haven't sorted out yet,
if that's necessary (1 for each type, it's ok I guess?)
