Merge branch 'conf_optimization' into 'master'

src/knot/conf/cf-parse.y

src/knot/conf/conf.c

src/knot/conf/conf.h

src/knot/conf/logconf.c

src/knot/ctl/knotc_main.c

src/knot/ctl/process.c

src/knot/main.c

src/knot/server/tcp-handler.c

src/knot/server/zone-load.c

tests/conf.c