Logchange2

Added in Nick's new changes as well.

Functional:
https://albino.pistoncloud.com/job/pentOS/10709/

Upgrade:
https://albino.pistoncloud.com/job/pentOS/10714/

Yeah this was basically for upgrade support with the concept that we would have one and only one Jenkins cluster, which was valid up until more recently.. As Jenkins cluster assignments will be richer going forward I'm in favor of unsetting and failing if CLUSTER isn't set. Let me make that change and get this back over to you..