add sanity check that $base is '.docbook'
add sanity check that $base is '.docbook'

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