knotd: finaliza D-Bus events

configure.ac

doc/man/knot.conf.5in

doc/reference.rst

src/knot/common/systemd.c

src/knot/common/systemd.h

src/knot/conf/base.c

src/knot/conf/base.h

src/knot/conf/schema.c

src/knot/conf/schema.h

src/knot/dnssec/context.c

src/knot/dnssec/context.h

src/knot/dnssec/key-events.c

src/knot/updates/zone-update.c

src/utils/knotd/main.c

tests/knot/test_confio.c