Support for the cd (checking disabled) bit.  Also remove data from the cache if validation fails.
Support for the cd (checking disabled) bit.  Also remove data from the
cache if validation fails.

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