[OpenAFS] rxtcp, rxutcp

[Jim Rees]

Are you talking tcp or udp?  If we had afs running over tcp, the ten-minute
ping would keep the connection alive unless your nat was really broken.

For the current udp implementation, I recently dropped in some code that
will reduce the ping interval to one minute.  We have discussed this on
openafs-devel in the past, and the consensus is that we don't want to offer
this option to the casual user because of the implications for the server.
So my code currently has no way to turn it on.