Generalized presence lists

[KoFish]

Rather than only storing one list per user on a HS the concept of lists could be abstracted into just having lists that certain users (private/public) can subscribe too. Similar to lists on twitter or facebook.

These would then work similar to how rooms work but instead just passing along the listed users presence events.

[ara4n]

Mmm, this would be really nice. Right now we do have early support for defining per-user presence lists seperate from rooms, but totally agreed that having arbitrary UNIX-group style lists that can then be used for ACLs, Presence, etc would be really nice.

Leo: how would this fit with the current presence-list management?

[leonerd]

Migrated to JIRA https://matrix.org/jira/browse/SPEC-46