Reduce or localize dependencies on address families.

Reduce or localize dependencies on address families.
* kdc_util.h (ADDRTYPE2FAMILY): New macro.
* do_as_req.c (process_as_req): Use inet_ntop instead of inet_ntoa.
* do_tgs_req.c (process_tgs_req): Ditto.
* dispatch.c (dispatch): Fix inet_ntop code, and use it always.
* kerberos_v4.c (process_v4): Check address family before copying out an IPv4
address.  Log if not IPv4, but continue.
* network.c (set_sa_port): New function.
(setup_port): Use it.  Combine IPv4 and IPv6 paths; IPv6 still disabled for
now.  Modify supplied sockaddr instead of making a copy.
(process_packet): SADDR is now sockaddr_storage.  Use socket-utils macros
instead of casting.  Enable the IPv6 code.

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@14602 dc483132-0cff-0310-8789-dd5450dbe970