[AFS3-std] rxgk-afs tokens for ptservers, etc.

[Benjamin Kaduk]

The rxgk-afs draft currently only mentions vlservers and fileservers, with 
only a passing mention of database servers.
If we want to stick to defaulting to the vlserver for GSSNegotiate, we 
should probably mention that other database servers are expected to be 
able to accept such tokens.
Alternately, we could specify that all database servers must offer the 
negotiation service, but that doesn't seem quite right.  (The bosserver 
will need special treatment, though, as we want to be able to use rxgk 
authentication to bring up the vlserver!)

Any thoughts one way or the other?

-Ben