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.
Sorry, I didn't understand that initially. 

In that case, I'd say bug 1046815 is invalid: we do not want the docker mozharness configs to be the same as the existing ones; we want, eventually, new configs and new mozharness scripts that don't do all this setup and don't need these links to release engineering servers.