Merge branch 'serial-policy' of /git/repositories/labs/knot

doc/reference.texi

man/knot.conf.5.in

samples/knot.full.conf

src/knot/conf/cf-lex.l

src/knot/conf/cf-parse.y

src/knot/conf/conf.c

src/knot/conf/conf.h

src/knot/server/zones.c

src/knot/server/zones.h

src/libknot/dnssec/policy.h

src/libknot/dnssec/zone-events.c

src/libknot/dnssec/zone-events.h

src/libknot/dnssec/zone-sign.c

src/libknot/dnssec/zone-sign.h

src/libknot/nameserver/name-server.c

src/libknot/nameserver/name-server.h

src/libknot/updates/ddns.c

src/libknot/updates/ddns.h