Matrix: a new specification for federated realtime chat

I've tested the Xabber 0.10 versions in F-Droid - the UI has finally caught up, but there's zero new functionality besides that and I also ran into tons of bugs using it. (And then Google's idea of OS package management helpfully destroyed a year of chat history when I tried to downgrade...)

I might switch to Conversations for the time being, or at least keep it around as a backup client.