Toggle display of the focused message's seen counter tooltip,
which shows which user have this message as their last seen
and when did they send that information.
When this mode is active, you can move the focus
to other messages and the tooltip will update itself.
If a message doesn't have a counter, it won't have a tooltip.
python_debugger (shift+F1) will now always start pdb, and
python_remote_debugger will always start remote_pdb.
Since the new autoreload.py script doesn't break stdin like entr with
live-reload.sh did, we can now use pdb if the app is connected to a
terminal.
