GRAV138  - This one wins the prize.   It does not seed the RNG, but still
           runs differently every time (like PLAS371...)   Also, this one
           is a bit smoother than the original.

GRAV139  - This one came in second.  Also, it doesn't look as good as the
           GRAV138.

GRAV-STK - An interesting but incomplete approach to optimizing a gravity
           program.  It has a few bugs still, but if you can shrink it or
           fix the problems, please e-mail Andy Kurnia (see the source).
