Adds initial empty files.
Creates some initial method/class structure.
Sets up board initialization and display.
Adds Piece perform_slide and perform_jump.
Adds Piece#perform_moves! to execute sequences of moves.
Adds Board#dup and a better unicode char for man pieces.
Adds Piece#valid_move_seq? and safe perform_moves.
Fixes an issue with perform_moves andadds promotion to king. Also improves king icon.
Implements playable game class with human players.
Adds victory conditions.
Lots of refactoring and clean-up. Also improves user input handling/validating.