THINGS TO DO:

THING DONE:

* add 4-direction robot code from Tom.

* use GNU Autoconf for platform independence

* cleaned up NEWS file.

* made sheilds, energy, score into long variables.

* allow this usage:
  robots --sheilds=100 --energy=1000

* added new demo robot programs.

* add some Scheme functions for the user to check on the shields level
  and energy level, so the robot can somehow respond to these
  conditions.
