Test shouldTransfer by upping a testserver and sending the SOA query.
Remove state from DefaultErrorHandler and just get it from the request.
Add more logging to show what is going on.
This also adds the infrastructure for future tests.
If monitoring is enabled for one zone, also enable it for when the
server reports REFUSED. Normally the metrics are only enabled if
you enter the middleware, with this you'll see REFUSED queries.
Each of these are reported agains the root zone otherwise
For prometheus use the plain value, not a pointer and change all usages.
Allow AXFR to be requested over udp as well and some other more log
printed when commencing an AXFR.
Respond to notifies and allow a secondary to follow the SOA parameters
to update a zone from a primary. Also sprinkle it with logging.
Also extend monitoring to include qtype in more metrics.
