Previously, the number of RRs in the RRSets were internally unlimited.
As the data structure that holds the RRs is just a linked list, and
there are places where we just walk through all of the RRs, adding an
RRSet with huge number of RRs inside would slow down processing of said
RRSets.
Add a configurable limit to cap the number of the RRs in a single RRSet.
This is enforced at the database (rbtdb, qpzone, qpcache) level and
configured with new max-records-per-type configuration option that can
be configured globally, per-view and per-zone.
Explicitly use an empty 'trust-anchors' statement in the system
tests where it was used implicitly before.
In resolver/ns5/named.conf.in use the trust anchor in 'trusted.conf',
which was supposed to be used there.
This commit extends the 'doth' system tests with additional secondary
NS instance that reuses the same 'tls' entry for connecting the the
primary to download zones. This configurations were known to crash
secondaries in some cases.