Changes for version 0.5
- Fixed two bugs:
- allow en-passant while in check (it is possible that a pawn moves 2 squares checking the enemy king, and a legal en-passant move can get out of check). Thanks Alan Curry.
- A move b2xa1=Q (promote black pawn by capturing pawn from a1) was interpreted as en-passant and always cleared field a2.
represent chess positions, generate list of legal moves, parse moves in various formats.