Version 1.2.1 released

This version fixes an issue with the steering controls, which was pointed out by FiveBitGames, and for which a possible explanation was suggested by xXx_Bobby Cage_xXx. Thank you both! It turned out Bobby Cage was right; the frame rate code (to make the game run at the same speed on different systems) was not properly applied to the steering, so on some computers this would be too fast. Now it has been fixed for Windows and Linux.