Cut off quiescent as soon as we see an unusable move
Cut off quiescent as soon as we see an unusable move

We always order captures before noncaptures (with the exception of transposition
moves, which are disabled in quiescent search) so we can stop as soon as we see
a noncapture in quiescent search

jwatzman/nameless-chessbot,jwatzman/nameless-chessbot