PgnViewerJS should accept Long Algebraic Notation in various forms

[mliebelt]

Currently the reader does not understand the Long Algebraic Notation, so code like

pgnReader({pgn: '4... Nf6xc4', fen: 'r1bqkb1r/pppp1ppp/2n2n2/4p3/2B1P3/5N2/PPPP1PPP/RNBQ1RK1 b kq - 5 4'});

results in the following error

SyntaxError: Expected " ", "!!", "!", "!?", "#", "$", "(", "*", "+", "0-1", "0:1", "1-0", "1/2-1/2", "1:0", "=", "?!", "?", "??", "D", "{", "∞", end of input, or integer but "x" found.

The reason for that is that only disambiguation (column XOR row) is allowed, but not both like in Nf6xc4.

See the documentation to move() in chess.js with the sloppy flag what should be possible out of the box.

[mliebelt]

Works for some long notations, close the issue for that. Not all possible formats are supported.