presence: Handle presence events #1618
Description
In the initial version of presence #196 / #1607, I plan to omit handling the presence event, to get the feature out ASAP.
The consequence is: when an offline user comes online, it might be up to a minute until the UI updates accordingly. The UI will eventually update, though, which is why I think it's OK to postpone this for a little bit.
We'll need to handle the event in its current form (awkward; I'd like to avoid spending time on it right now) and in a future updated form; see discussion: #api design > presence rewrite @ 💬