update controllers to new paper trail

app/controllers/home_controller.rb

@@ -15,6 +15,6 @@ class HomeController < ApplicationController
       end
       return redirect_to cfp_root_path
     end
-    @versions = Version.where(conference_id: @conference.id).includes(:item).order("created_at DESC").limit(5)
+    @versions = PaperTrail::Version.where(conference_id: @conference.id).includes(:item).order("created_at DESC").limit(5)
   end
 end

app/controllers/recent_changes_controller.rb

@@ -5,7 +5,7 @@ class RecentChangesController < ApplicationController
 
   def index
     authorize! :manage, CallForPapers
-    @all_versions = Version.where(conference_id: @conference.id).order("created_at DESC")
+    @all_versions = PaperTrail::Version.where(conference_id: @conference.id).order("created_at DESC")
     @versions = @all_versions.paginate(
       page: page_param,
       per_page: 25
@@ -18,7 +18,7 @@ class RecentChangesController < ApplicationController
 
   def show
     authorize! :manage, CallForPapers
-    @version = Version.where(conference_id: @conference.id, id: params[:id]).first
+    @version = PaperTrail::Version.where(conference_id: @conference.id, id: params[:id]).first
   end
 
 end

app/models/conference.rb

@@ -193,11 +193,11 @@ class Conference < ActiveRecord::Base
     if self.timeslot_duration_changed? and self.events.count > 0
       old_duration = self.timeslot_duration_was
       factor = old_duration / self.timeslot_duration
-      Event.paper_trail_off
+      Event.paper_trail_off!
       self.events.each do |event|
         event.update_attributes(time_slots: event.time_slots * factor)
       end
-      Event.paper_trail_on
+      Event.paper_trail_on!
     end
   end
 

lib/static_program_export.rb

@@ -209,7 +209,7 @@ class StaticProgramExport
   end
 
   def unlock_schedule
-    Conference.paper_trail_off
+    Conference.paper_trail_off!
     @conference.schedule_public = true
     @conference.save!
   end
@@ -217,7 +217,7 @@ class StaticProgramExport
   def lock_schedule
     @conference.schedule_public = @original_schedule_public
     @conference.save!
-    Conference.paper_trail_on
+    Conference.paper_trail_on!
   end
 
 end