Add castling to Chess960

[landofrhymeandraisins]

In Chess960 you're supposed to be able to castle, which puts the king and rook on the same spots they'd end up on in normal chess. The rules are about the same as in normal chess, but there would need to be some extra coding I suspect. There are some Chess960 positions where the king stays in the same spot when castling (any position where the king is already on the c file or the g file), so a castle button might be necessary.

[Wingdinggaster656]

Yes, you would be correct.

This is something that has been bothering me for a long time too, but it is not easy to solve it now, because the root cause of this problem is actually a library used by MAS, not MAS itself.

Either we completely rewrite MAS chess so that it no longer requires the use of that library (which is impractical and unnecessary), or we wait until MAS updates to renpy 8 and starts using Python 3 in the future so we can update this library to a problem free version.

@ThePotatoGuy May you consider adding updating the chess library to the Post Python 3 Milestone?