Woohoo! Threading is a separate plugin now!

- Get threading service from "annotator.threading"
- setup up newly created annotations in the threading
- move draft management around a bit, to make it more automatic
  with the annotation lifecycle events
- simplify the logic of the Store monkey patch
- pass annotations to the Editor controller via showEditor
  rather than relying on on the id in the params, reducing reliance
  on temporary ids, now added by the threading plugin