This is functionally the same as --server, but provides some syntactic sugar to
make specifying address-to-name queries easier.
For example --rev-server=1.2.3.0/24,192.168.0.1 is exactly equivalent to
--server=/3.2.1.in-addr.arpa/192.168.0.1
Signed-off-by: DUPONCHEEL Sébastien <sebastien.duponcheel@corp.ovh.com>