Have the ipropd-master listen on an IPv6 socket in addition to an IPv4
socket to allow propagation of changes to a Heimdal Kerberos database
from the KDC master to the slave(s) work on IPv6 as well.

Update the stats logging to also handle IPv6 addresses.

Reported by:		peter (found on FreeBSD cluster)
X-to-be-tested-by:	peter
MFC after:		3 weeks