Remove inet_ntoa() prototype from getrpcent.c

It is not needed.

In general, we shouldn't be using inet_ntoa(), anyway, as it is
IPv4-specific and we have IPv6 support almost everywhere.
Add new versions of log_badauth gssrpc callbacks

libgssrpc supports two callbacks for gss_accept_sec_context failures
on servers (one for AUTH_GSS and one for AUTH_GSSAPI), which are
IPv4-specific.  Provide an alternate version which supplies the
transport handle instead of the address, so that we can get the
address via the file descriptor for TCP connections.

ticket: 7770
Correctly log IPv6 addresses in kadmind

Define client_addr() in server_stubs.c and use it consistently in that
file and ipropd_svc.c to get the client address from a transport
handle.  In it, call getpeername() on the client socket and use
inet_ntop() on the result, instead of using inet_ntoa() on the IPv4
socket address.  Provide a log_badauth2 callback to GSSRPC, so that we
get a transport handle instead of an IPv4 socket address, and use
client_addr() within it instead of inet_ntoa().

ticket: 7770
target_version: 1.12
tags: pullup
Bump libgssrpc minor version

Bump minor version for the new log_badauth2 interfaces.

ticket: 7770
Update kvno doc to match usage

-C, -u, and -k were undocumented but printed in xusage().
(-q and -h are not mentioned in either place.)

While here, add a note that kvno is a debugging tool and need
not be used in regular operation.

Reported in Debian bug #698605.