Fixed bug where GTP String was not correctly generated due to counting errors

refs #28 @0h20
Child proc now initiates desired ai based on e_useai settings
Fixed bug where PlayPolicy got a segfault due to nullpointer in board member.

refs #27 @3h0
Child procs now generate a move and return it in GTP format "= pos". Now using int instead of board pos for simplicity. Purely internal function so only int allowed.
Should instead return a list of calculated positions in the form:
"= pos[0],expected[0],timesPlayed[0];pos[1],expected[1],timesPlayed[1];...;pos[n],expected[n],timesPlayed[n];

refs #27  @2h0