transferring attributes by name (instead of en masse) from world to robot, for clarity
reduced info per robot being sent to browser (fewer fields, fewer sig-figs per field)
changed aim register so it never goes above 360
moved three-sigs logic into physics
fixed merge conflict from stash
curtailed amount of info (And sig-figs) sent for shells
changed comments in robot
got billiard ball collision detection almost working (still wonky)
couple of bug fixes on collision detection
implemented 'damage' to robots on collision

although they don't die yet -- their capacity
for damage is infinite.

also, the damage is just one point per collision --
it's in no way proportional to kinetic energy yet.
rewrote the robot source programs to take evasive action upon damage
got some animation going for shell explosions and robot collision damage
reduced range of top shooter and left shooter
moved shell and shell-id to top level of world