Support the standard forum-format (custom parser)

[artasparks]

This is the standard used by Sensei's library: http://senseis.xmp.net/?HowDiagramsWork

It's a pretty deficient format compared to SGFs but it might help Glift adoption elsewhere.

Example format:

$$ A [joseki] variation
$$  ------------------
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . 7 3 X d . . .
$$ | . . O 1 O 6 . . .
$$ | . . 4 2 5 c . . .
$$ | . . 8 X a . . . .
$$ | . . . b . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .

[artasparks]

Writing parsers is easy, but I'm not sure how impactful this is. If someone came to me requesting this and assured me that it would be used, I would consider working on it. Backlog for now.