utils: improve params processing

src/utils/common/exec.c

src/utils/common/msg.h

src/utils/common/netio.c

src/utils/common/params.c

src/utils/common/params.h

src/utils/common/resolv.c

src/utils/common/rr-serialize.c

src/utils/common/token.c

src/utils/dig/dig_exec.c

src/utils/dig/dig_params.c

src/utils/host/host_params.c

src/utils/nsupdate/nsupdate_params.c