Merge branch 'sign_queries_with_tsig' into 'master'

src/knot/ctl/remote.c

src/knot/nameserver/axfr.c

src/knot/nameserver/internet.c

src/knot/nameserver/ixfr.c

src/knot/nameserver/nsec_proofs.c

src/knot/nameserver/update.c

src/knot/server/notify.c

src/knot/server/notify.h

src/knot/server/tcp-handler.c

src/knot/server/xfr-handler.c

src/knot/server/zones.c

src/knot/updates/xfr-in.c

src/knot/updates/xfr-in.h

src/libknot/packet/pkt.c

src/libknot/packet/pkt.h

src/libknot/rrset.c

src/utils/common/exec.c

tests/pkt.c