If an NFS server is only listening on TCP for portmap (as apparently

MS-Windows-Server2003R2SP2 does), mount doesn't cope.  There is retry
logic in case the initial choice of version/etc doesn't work, but it
doesn't cope with mountd needing tcp.
So:
  Fix probe_port so that a TIMEDOUT error doesn't simply abort
    but probes with other protocols (e.g. tcp).
  Fix rewrite_mount_options to extract the mountproto option before
    doing a probe, then set mountproto  (and mount prot) based
    on the result.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Steve Dickson <steved@redhat.com>