add limited scope, keyed ssh scripts to perform buildbot status queries, and restarts

[Jeff Johnson]

any chance of putting a 'what are you doing?' and a 'poke it with a stick'
script on a box mats has access to?
and so to permits mats, when he notices a seemingly dead BB,
and you are out of pocket, to remediate it

or perhaps then just a usage note he can consult

via a restricted ssh command to do limited keyed access and a specific task, to
compartmentalize possible priv escalations in the event of a compromised
machine