misc/mtail: Start of an mtail config Stashing it here in case anyone wants to continue working on it. Currently it's only counting log messages by level. Due to the permissions set by systemd on Prosody logs, mtail never managed to start correctly until permissions were manually relaxed.

This module discards typing notifications sent to a bare host JID,
preventing error replies to be sent. These errors are harmless but can
be annoying sometimes if your client shows them prominently.