Mods to bring staff creation in line with devise 3.1.

(Note: staff/update is NOT working. Still TODOs).

++++++++++++++++++ Devise Customization ++++++++++++++++++++++++++++++
   We need to allow 'sign_up' by a third party. In other words, it is
   a admin type role that regiesters users. Devise's model is that user
   signs up for himself. This is enforced by requiring current user NOT to
   be authenticated when signing up, ie exercising new/create methods of
   registration controller.

   We circumvent this constraint by:
   1. Creating new and create proxy actions in StaffController, new_staff and create_staff,
   respectively. And, of course, adding appropriate routes. We create these proxies so
   step 2 works. If we enter new/create at Devise::RegistrationsController, we can not
   leverage skip_before_filter.
   2. Using skip_before_filter for :require_no_authentication and limit this "skip"
   to new_staff and create_staff actions.
   3. Directing new user request to new_staff and create user request to create_staff. The
   former occurs on staffs/index view, the latter on new staff form.
   4. Over-ride after_sign_up_path to return to staffs/index.
   5. Over-ride sign-up to be a no-op so that admin is not logged and newly registered
   user logged in (default behavior of devise).

   We also customize build_resource to setup associations.
Merge branch 'rails-31' of github.com:rkgordon3/radar into rails-31