Release version 0.17.0 (#72)

Codable conformance (#71)

Add missing items from 0.16.0 changelog

Release version 0.16.0 (#70)

Prepare for 0.16.0 release

Replace `BoardDelegate` with `Board.State` (#69)

Improve appearance of board state example in readme

Fix Board.update(position:) documentation

Remove unnecessary pgn conversion in game tests

Add board state to readme

Replace board delegate with state property and update documentation

Fix result PGN parsing and disambiguation SAN parsing (#68)

parsers_bug_fixes - restored sample pgn castling to use Os instead of zeros

parsers_bug_fixes - moves resulting in a check or checkmate fails regex test and are not disambiguated.

parsers_bug_fixes - added '½' as a supported result token character.