improvements in the openafs codebase

[Benjamin Kaduk]

Hi all,

Thanks to some very useful pointers from kib@, I've fixed up the locking 
around our calls to vgone(), which seems to have improved the stability of 
the codebase quite a bit -- along with a trivial lock-order fix for 
lookup, this lets a parallel buildworld complete on my four-core machine.
The code isn't in an OpenAFS release, yet, and I haven't made time to 
squash all of the patches together on top of a release, but I did update 
the git-based port, which can now be found at:
http://web.mit.edu/freebsd/openafs/openafs-devel.shar.txt

I'm planning on submitting to the Ports Collection once I write an rc 
script and tidy up the packaging; hopefully OpenAFS 1.5.78 will be out by 
then to simplify the patching phase.

-Ben Kaduk