algorithm to more closely follow RFC1035, so that root servers will
provide a more complete set of name server glue addresses in ccTLD
referral responses.

For non-referral responses, the server no longer uses glue as
additional data.

For referral responses, the servers now looks for glue A/AAAA/A6 RRs
in the zone where the NS RRs reside, even in the case where this is
different from the zone where the A/AAAA/A6 RRs would have resided had
they been authoritative data.

A6 chains included as additional info may not yet fully follow these
rules.