Log rotation

[strugee]

We need to handle log rotation "somehow" (whether that be internally or just being able to deal with external tools like logrotate).

[detrout]

I think the common solution is a signal that tells the daemon to close and reopen the log.

So logrotate renames the current log file, sends the signal, and the daemon opens (possibly creating), and starts writing to the new log file.

[strugee]

Seems reasonable.