Document `-d' and `-I'. Add a BUGS section noting that
logging from UDP is an unauthenticated remote disk-filling service,
and probably should be disabled by default in the absence of some sort
of authentication.
so that it only unlinks the file if syslogd knows it created it.
If the path specified for the socket already exists then syslogd
will now exit with an "address already in use" error which is more
sensible than blindly unlinking the existing filename. This stops
syslogd -d foo/bar from unlinking foo/bar if it's a real file.
