RX Kerberos 5 security class requirements of Kerberos library

[Love Hörnquist Åstrand]

rx can't use in the general case kerberos messags anyway because of  
size limitations
in the crypto/auth hand-shake.

Creating a "rxk5" token that can exchanged over clear-text rx rpc's  
protected
with kerberos 5 messages is IMO the way forward.

Then in the service to service case, the src service and print "rxk5"  
token to it hearts content
without even dealing with Kerberos.

Love