- fix buffer scroll correction when adding lines
- buffer_seen broadcast is a bit racy, lessen the racyness by adding
  buffer-last-activity timestamps and look whether the broadcast
  timestamp is newer before removing the highlights
  (this might also be useful in other places?)
- make a buffer list sorted by last activity
- fix problems when backend goes offline => clear states etc.
- add startup buffer config selection
- fix the coro edge world problem
- fix off-by-one bug in msgline
- add shutdown function other than ctrl-c to backend
- add history log for reconnects of the frontend
- add tcp keep alive to Net::IRC3?
- improve irc mode setting and general any channel actions
  - make irc invites being displayed etc.
- make /presence command (for IRC it toggles just away status)
- add smarter subscription commands for irc, etc.
- add groupings of buffers
  - rework buffer handling => make client more OO

- add XMPP support with Net::XMPP2 (which still isn't released)
- allow correct display of multi-line messages

future:
- implement formatted messages (for wrap-padding and colors)