Support logging to syslog

Simply set the logfile path to "syslog" and murmur will log to syslog.

This should be stable, it has approximately 4 user-months of testing.
`qfLog` is initially assigned NULL, and only ever assigned in L339 above, which is in the `if`-part. Thus, this statement is never useful / in no case changes the value of `qfLog`, right?