Merge remote-tracking branch 'origin/new-ixfr' into development

src/knot/other/debug.h

src/knot/server/xfr-handler.c

src/knot/server/zones.c

src/knot/zone/semantic-check.c

src/knot/zone/zone-dump.c

src/knot/zone/zone-load.c

src/libknot/dname.c

src/libknot/dname.h

src/libknot/hash/cuckoo-hash-table.c

src/libknot/hash/cuckoo-hash-table.h

src/libknot/nameserver/name-server.c

src/libknot/packet/packet.c

src/libknot/packet/packet.h

src/libknot/packet/response.c

src/libknot/rdata.c

src/libknot/rrset.c

src/libknot/updates/xfr-in.c

src/libknot/updates/xfr-in.h

src/libknot/util/debug.h

src/libknot/util/error.h