nfs4_acls: Mark nfs4:acedup ignore and reject as deprecated

nfs4_acls: Mark nfs4:acedup ignore and reject as deprecated

The default setting for nfs4:acedup is "dontcare". The only
recommendation i could find is setting this to "merge". The setting of
"ignore" is dangerous as it would silently drop ACEs. "reject" also
seems less useful as it would disallow setting of ACLs that can easily
be stored.

Report "ignore" and "reject" as deprecated. Maybe these can be removed
in the future to simplify the code.

Signed-off-by: Christof Schmitt <cs@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>