Allow parent controller to be customizable.

CHANGELOG.rdoc

@@ -8,6 +8,10 @@ Notes: https://@plataformatec/devise/wiki/How-To:-Upgrade-to-Devise-2.0
   * Allow alternate ORMs to run compatibility setup code before Authenticatable is included (by @jm81)
   * Do not run validations unless on reconfirmable branch
 
+* enhancements
+  * allow parent controller to be customizable
+  * inherit from the same Devise parent controller (by @sj26)
+
 == 2.0.0.rc
 
 * enhancements

app/controllers/devise_controller.rb

@@ -1,4 +1,4 @@
 # All Devise controllers are inherited from here.
-class DeviseController < ApplicationController
+class DeviseController < Devise.parent_controller.constantize
   include Devise::Controllers::InternalHelpers
 end

lib/devise.rb

@@ -214,6 +214,11 @@ module Devise
   mattr_accessor :sign_out_via
   @@sign_out_via = :get
 
+  # The parent controller all Devise controllers inherits from.
+  # Defaults to ApplicationController.
+  mattr_accessor :parent_controller
+  @@parent_controller = "ApplicationController"
+
   # DEPRECATED CONFIG
 
   # If true, uses salt as remember token and does not create it in the database.