remove unused mixin
introduce Speed
bump v 2.15
Upgrade scalalib
build Speed from Clock
remove wrong comment
test and implement FEN import with castles and turns
Add FromPosition variant
Allow to castle by moving king to rook in standard chess
FromPosition variant does not store the pieces positions
titivate dumper code
improve FEN parser
minor tweaks
read the game turns from pgn
tolerate fen strings without full move number
Improve forsyth api
validate board and situation
stricter board situation validation
strictness of board validation
make Replay a case class, improve Situation api