PGN parser

[kevinludwig]

Hi,
I found your repo because of my interest in a variant of chess.js that supports RAV. Separately, I've written a full-featured PGN parser that handles the full spec, including commentary and RAV. It uses peg.js (a javascript parser generator), so it's pretty concise. It might simplify the work you have here, if you happen to be interested: https://github.com/kevinludwig/pgn-parser.