Add a user preference to choose how comments/replies are displayed: in chronological or reverse chronological order (#589, #776).

git-svn-id: http://redmine.rubyforge.org/svn/trunk@1197 e93f8b46-1217-0410-a6f0-8f06a7374b81

app/models/user_preference.rb

@@ -46,4 +46,7 @@ class UserPreference < ActiveRecord::Base
       self.others.store attr_name, value
     end
   end
+  
+  def comments_sorting; self[:comments_sorting] end
+  def comments_sorting=(order); self[:comments_sorting]=order end
 end