Bug 1046815: Update mozharness configs

This almost re-syncs our mozharness config files with the "real" ones in mozharness. The remaining differences are a few references to /tools; I am trying to sort out those differences with Release Engineering, but that may take some time.
Same thing here... `.pvt.` sounds like things we can't use.
Does it make sense to add these then?

IMO, if we need binaries and things like that we should put them on the image... Ideally, the whole virtualenv should be setup on the image when we upload it. (Note, I'm not entirely sure I know what I'm talking about)