Fix this.redirect in RouteController...

- Closes Issue #469.
- We now give the user a warning if they call stop() in a RouteController
  function during a run. This is because it is unlikely the user wants to stop
  the entire controller from running. They just want to pause downstream
  functions from running (e.g. before/action/after) if some condition is not
  true in the current computation's run. But when you redirect you *really* do
  want to stop the controller.
- Solution: The Router can call a "private" function to stop the previous
  controller from the run method of the router.
- Test it out.