Move the token faking code out of superuser-t.c into its own file in
tests/common, so it can be used by other tests.
Change-Id: I7b420250ef974b4b80a8dde692d2666657bb82ca
Reviewed-on: http://gerrit.openafs.org/7259
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@dementix.org>
