Meetingbot config file

[jaimejim]

I am running the bot on my server. I have removed the -p argument and use -A instead, with a hardcoded password (sorry). I am just running it as a background process at the moment (using "&").

It'd be nice to add a config file for the arguments instead. I believe aioxmpp supports that already. That'd help to run it with a nice process manager or on docker.

[mnot]

I think the aioxmpp example code in framework.py supports it. I'm reluctant to make changes there, though...