Add initial load of queued action id's for actionWatcher
Refactor Action and ActionResult...

... to facilitate queueing and identifying actions pending for a given Unit (and in future for a Service, etc.)

Also, add tests for actionWatcher refactor.
Merge pull request #216 from johnweldon/actions-watcher-redux

Actions watcher redux

Make sure Actions queued before a watcher starts are picked up when the watcher does start.

Also slight refactoring to prepare for Actions being queued on Services as well as Units