also add some doc for the marquee plugin

Fix subtle bugs hopefully without introducing new ones

Fix a traceback on /w, and many other places, when a MucListTab is open

If by change a user manages to connect to gmail, they won’t be able to
join another server that has MUCs, so that code is useless.

We want to be able to run "python -m poezio" AND have a poezio entry
point.

otherwise it breaks the generated entry point loader, which will work
but display a traceback on exit

And fix a breakage due to the recent change in tab creation.

fixes the circular import issue

All this crap is very brittle due to circular deps and python handling
them badly. This appears to be fixing some stuff, at the very least.

This is sed, so cleanup of imports (which can now be grouped together)
is not done yet.

Instead of chat tabs, which include MUC which doesn’t implement that.

broken since bc6ee8da due to using timestamps

(even if we thought we were already disconnected)

(broken during linkmauve refactoring)

It’s needed for proper installation