Merge branch 'master' into chain-fix

src/knot/server/zones.c

src/utils/dig/dig_exec.c

tests-extra/README

tests-extra/data/.zone

tests-extra/tests/axfr/bind_knot/test.py

tests-extra/tests/axfr/knot_bind/test.py

tests-extra/tests/axfr/knot_knot/test.py

tests-extra/tests/basic/nsec/test.py

tests-extra/tests/basic/nsec3/test.py

tests-extra/tests/ddns/prereq/test.py

...xtra/tests/dnssec/dnskey_timestamps/data/example.com.zone

tests-extra/tests/dnssec/dnskey_timestamps/test.py

tests-extra/tests/dnssec/none_to_nsec/test.py

tests-extra/tests/dnssec/none_to_nsec3/test.py

tests-extra/tests/records/empty_rdata/data/empty.zone

tests-extra/tests/records/empty_rdata/test.py

tests-extra/tests/records/obsolete/test.py

tests-extra/tests/zone/load/test.py

tests-extra/tools/dnstest/__init__.py

tests-extra/tools/dnstest/keys.py