makes ballot's back link point to referer

app/controllers/budgets/ballot/lines_controller.rb

@@ -7,8 +7,8 @@ module Budgets
       before_action :load_ballot
       before_action :load_tag_cloud
       before_action :load_categories
-
       before_action :load_investments
+      before_action :load_ballot_referer
 
       load_and_authorize_resource :budget
       load_and_authorize_resource :ballot, class: "Budget::Ballot", through: :budget
@@ -73,6 +73,10 @@ module Budgets
           @categories = ActsAsTaggableOn::Tag.where("kind = 'category'").order(:name)
         end
 
+        def load_ballot_referer
+          @ballot_referer = session[:ballot_referer]
+        end
+
     end
   end
 end