Added capability of FSAL to tell Ganesha not to cache a particular entry
Do not allow access which is denied by previos ACEs.
Access check for OPs should break with EACCESS if a required bit is
denied by an ACE.
Access check for ACCESS OP should continue scanning the ACEs to return
correct set of allowed ops, but access once denied should not be included
if it is allowed by subsequent ACEs.

Signed-off-by: Srikrishan Malik <srimalik@in.ibm.com>
Do not reset bits in allowed set.
This can deny permissions to root.

Signed-off-by: Srikrishan Malik <srimalik@in.ibm.com>
Save UDP request remote port number in svc_req, since UDP xprt
is shared among different endpoints of the same host addr.
This port is needed to send data gram response back
to client.

Signed-off-by: Rong Zeng <rongzeng@us.ibm.com>