v6.0.0-beta-3

This is the third beta of 6.0.0, featuring the new rust based parser.

This should be more or less stable - You can track my testing progress here: #267 - if it isn't marked as tested, it's probably still broken.

Your mod cache will be rebuilt using this beta (and every for every version that comes after this - I feel it's fast enough now, and it let me dump a ton of conditional tests on updates)

Please report problems, comments, or suggestions in #267