No real progress feedback while a run is executing

[LionsPhil]

The feedback mechanisms for a run in progress are not yet implemented, beyond running/completed. There are plans for plumage_run to aggregate the logs and the Client to provide a server-sent events feed to the UI. This is very important when doing test configuration development where Polygraph may be throwing errors, since currently the only way to see them is to SSH onto the Client and dig them out of the state directory. There's also work to be done around this area in properly reporting runs which were aborted.

It should also be easier to see when a Client/Server pair are busy to avoid scheduling another run on top of them.