libafsauthent: Export more token-manipulation functions

libafsauthent: Export more token-manipulation functions

For both Windows and Unix.

Reviewed-on: https://gerrit.openafs.org/13129
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Michael Meffie <mmeffie@sinenomine.net>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
(cherry picked from commit 1974eac772157651594c1b76ea8f55e4567b3ec5)

Change-Id: I7b26772fe9f447ac1cf562eb5837a6035d8f0175
Reviewed-on: https://gerrit.openafs.org/13181
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Michael Meffie <mmeffie@sinenomine.net>
Reviewed-by: Andrew Deason <adeason@sinenomine.net>
Reviewed-by: Joe Gorse <jhgorse@gmail.com>
Reviewed-by: Marcio Brito Barbosa <mbarbosa@sinenomine.net>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>