Add :add_me action on eventscontroller: quick add person.

Listens to PUT, redirects to event.
Adds current_user as person to event, with role coordinator and status
confirmed.
Is only availble for admins, b/c of before_filter.
Add a button to fire the :add_me action.
Redirect back to event_people, not event-page
Merge branch 'feature/ownership' into develop

* feature/ownership:
  Redirect back to event_people, not event-page
  Add a button to fire the :add_me action.
  Add :add_me action on eventscontroller: quick add person.