updated ring condition - not only empty fields must be checked, TODO
repair this
fixed ring condition, board size 5 doesn't work anymore - needs to be
fixed
cleanup, testing if boardsize 5 works
improved board to string
added command line argument parser and evaluation
updated evaluation bdd - includes winning condition for white and
not-winning condition for black
hgf parser implemented
color for player and color for cpu are free to set, can be read from an
hgf file
fixed the hgf parser