version 0.93 (public): (hi)score, better pickup/multiple movement

version 0.93 (public): (hi)score, better pickup/multiple movement

# torpedo-upgrade was cleared when firing torpedo at the end of level
* pickups move half the speed of enemies (one pixel every 2 turns)
# fixed a bug causing some calcs to crash on quit
# contrast was not restored after game over (remained one step darker)
* fire key changed from F1 to 2ND, select key changed from F2 to ALPHA
* improved key-checking procedureS (much faster, smaller, better, yea)
* changed title screen, displays version white on black and my e-mail
+ score count!! simple system: one point for an enemy destroyed, two
  for collision, and 1 point every 256 frames. plus level clear bonus
+ saves HISCORE!!! At game-over screen your and hi-score are displayed
* Game over screen will be displayed before quit after pressing <exit>
+ screen is cleared and cursor moved to top-left on quit
* multiples move only when YOU move, just like the original MSXNemesis
* multiple is placed at your position when selected/at start of level
* minor changes in iconbar (3rd icon is empty, line between 5th/score)