com 4, com 3 to HeroesChessGUI

getting closer, but something weird still happening when moving white.
turn changes to black before white player's currentMove updates, which
causes a nullpointerexception.
com 4, com 4 to heroeschessgui

almost made it working! it does but breaks after a few moves... not sure
why. also, the solution to keep all gui pieces updated based on latest
bitboards is too heavy. it's using a for-loop through all 64 positions
and recreating and repositioning all gui pieces after every move. a
better solution must be only updating the pieces actually moving/dying.