Action results

*Action Results* in the State
==

An Action can now be `Fail()`'ed or `Complete()`'ed, and the relevant output will be stored in the `actionresults` collection in the juju db in mongo.

The reason, or the output will be written to the `ActionResult`, along with the details of the `Action`.

The prefix of the `ActionResult.Id()` will also encode the `Action.Id()` from which it was generated (which itself encodes the `Unit.globalKey()` that the `Action` was queued for.
Never mind - I just saw the ActionResult type further down. 

In that case how about a type of ActionStatus and a field name of Status. That way there's a clear difference between the concept of the end state and the actionResultDoc/ActionResult struct.