ignore list for unitsync hashes

[BrainDamage]

there should be an unhashed ignore list for unitsync content hasher, so files and folders can be added to the archive without getting indexed nor breaking sync hashes (for example at the .svn metadata folder)

[aegis]

You don't NEED to verify vs the unitsync hash. You can simply send the synced bit if you know they are still compatible. (add a hidden debug checkbox in springlobby or something)

[BrainDamage]

spring does hash check as well (at least for mods) before starting the game, so it would NEED the feature ...