PATCH: add updater's signer-name to log

[Evan Hunt]

> [ originally sent to Michael Graff, but this is probably the better
>   place for it :]

An even better place is bind-suggest at isc.org, so it goes into our
ticketing system.  I'll forward it there now.

> Would this be suitable for inclusion in an upcoming BIND?

Yes.  Though I suspect we'll report the signer in a second log message
rather than changing the existing message, so as not to break any scripts
that might be grepping the log for the current pattern.

--
Evan Hunt -- each at isc.org
Internet Systems Consortium, Inc.