Cleans some more resource, view, controller stuff up with it.

- Listen to events for setting the user object after registration
  and login. This change reduces the amount of horus code duplicated
  by the AppController through integration with our enhanced user
  request property.
- Add response helpers to the AppController to even further reduce
  the amount of code duplicated from horus. So simple now!
- Keep the {flash, model} structure of the app's main JSON view
  known only to the view callable, not the resource. The resource is
  just the model now.
- Stop all that silly reifying
- Upgrade our flash message system to handle the FlashMessage class
  from bag.pyramid.flash_msg.
- Tweak some messages slightly.
- Change the way the app is created. First, load the modules which
  integrate with horus: forms, models, and schemas. Then, load horus
  itself. Finally, include all of h.