rename INVALID_POSITION to PIECE_NOT_FOUND

fix wrong error message when move indices are invalid

fix incorrect move notation when disambiguating moves

fix that en passant captures do not work

fix regression: position reporting about PGN errors

add 150 example games to test PGN parser

add test directory and make target for tests

make eval_move() and check_move() not change their input string

(0) -100 -30 -10 -8 tip

mercurial