add another game to test stalemate detection default tip

gamestate_cleanup() is now safe to be called multiple times

add FEN history to the game state

fix: wrong error code when king moves into check and missing auto-disambiguation when one of the candidate pieces is pinned

fix: disambiguation by row while capturing was not implemented

rename INVALID_POSITION to PIECE_NOT_FOUND

(0) -100 -30 -10 -6 tip

mercurial