Add command line options to enable those NFS versions that are
currently disabled by default. We choose to use the options '-V'
and '--nfs-version' for compatibility with rpc.mountd.
Acked-by: J. Bruce Fields <bfields@fieldses.org> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Steve Dickson <steved@redhat.com>