replace gta2 game settings with more mod options

the game settings (map, cops enabled, time, game type, ...) have been
replaced with new splitscreen hack options (merge all windows? sleep
time before merge, hide windows taskbar?) - also all layouts have 4:3
aspect ratio versions now (most of them have empty space - but the game
is more playable that way).
the new GUI inputs are - just like the ones before - not functional yet!