cmd: List version in help for commands

List version in help for commands using cmd library

Reviewed-on: http://gerrit.openafs.org/10956
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: D Brashear <shadow@your-file-system.com>
(cherry picked from commit 4b4d44b3dd62c2a36908f20eeff345b666e7858d)

Change-Id: I1c4881de710f5c48af5645bce64fbee4fb4854f2
Reviewed-on: http://gerrit.openafs.org/11214
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Chas Williams - CONTRACTOR <chas@cmf.nrl.navy.mil>
Reviewed-by: Stephan Wiesand <stephan.wiesand@desy.de>