Add variable auto_join_whitelist ?

[goiken]

I'd like to differentiate my auto-join behaviour by the discord servers. Some are small, where I'd like to subscribe to everything and others are massive, where I'm only really interested in a hand full of channels.

As far as I understand, to do that, currently I'd have to auto-join everything and tinker with a massive, list of exclusions.

Really, though, I'd much rater do something like acc discord set auto_join_whitelist s1, s3 to join everything on the servers s1 and s3 (and only on those, unless auto_join == true).

Analogously one could contemplate to add a blacklist of servers as well.