de-couple dns_zone_notify() and dns_zone_maintenance() from their callers.
de-couple dns_zone_notify() and dns_zone_maintenance() from their callers.

pecharmin/bind9,pecharmin/bind9,pecharmin/bind9,each/bind9-collab,pecharmin/bind9,pecharmin/bind9,each/bind9-collab,each/bind9-collab,each/bind9-collab,each/bind9-collab,pecharmin/bind9,each/bind9-collab