Restore permission documentation in bosserver man page

Restore permission documentation in bosserver man page

The original IBM HTML documentation had a table showing the permissions
that bosserver expects and sets when it creates the directory structure
for AFS.  That table was accidentally dropped in the conversion to POD.
Restore it from the HTML shipped with an older version of OpenAFS.

Reviewed-on: http://gerrit.openafs.org/210
Tested-by: Russ Allbery <rra@stanford.edu>
Reviewed-by: Russ Allbery <rra@stanford.edu>