add avatars

models.lua

@@ -12,6 +12,10 @@ function Users_mt:is_admin()
   return self.permission == constants.PermissionLevel.ADMIN
 end
 
+function Users_mt:is_default_avatar()
+  return self.avatar_id == nil
+end
+
 local ret = {
   Users = Users,
   Topics = Model:extend("topics"),
@@ -19,6 +23,7 @@ local ret = {
   Posts = Model:extend("posts"),
   PostHistory = Model:extend("post_history"),
   Sessions = Model:extend("sessions"),
+  Avatars = Model:extend("avatars"),
 }
 
 return ret