Merge branch 'knsupdate_prereq' into 'master'

man/knsupdate.1.in

src/libknot/rrset-dump.c

src/libknot/rrset-dump.h

src/utils/dig/dig_params.c

src/utils/host/host_params.c

src/utils/nsupdate/nsupdate_exec.c

src/utils/nsupdate/nsupdate_params.c

src/utils/nsupdate/tests/test_knsupdate

src/utils/nsupdate/tests/test_nsupdate