gss callback patches

[J. Bruce Fields]

The following 3 patches are all we need to get gss calbacks working.
The 3rd is actually purely server-side.  Could I get your ack or nack on
the first two?

I'm asking for an ack rather than asking you apply them because I think
I'd rather submit them through the server tree, which is more likely to
have conflicting patches--though either way could probably be made to
work.

--b.