mod_muc_bot: Save occupant to room
This has some side-effects:
Firstly, the bot shows up in occupant list, which is nice. Secondly, the
bot starts receiving messages from the room which might be wanted, but
it would be better to join the room for real in this case.
2c07bcf56a36d6e74dc0f5422e89bd61f4d31239 0.8-diverge
1656d4fd71d07aa3a52da89d4daf7723a555e7dd last-google-code-commit