Urf. It pains me to see us putting using `log.Printf` for such information. I know that we don't yet have a better story for generating output that doesn't come from within a plugin (i.e. no runner exposing LogError and LogMessage) but I still think we should move in the right direction. Maybe this could populate a data structure w/ the raw output data and pass that data structure to another method which handles the output? It would also be good to get this info into Heka's internal report which can be written to stdout or the DashboardOutput.