Can't revert due to incompatibility of new site setting types.

Revert "Revert "FEATURE: Site settings defaults per locale""

This reverts commit 439fe8ba2453cff835cda33a5593bb9fa769120c.

lib/discourse.rb

@@ -84,6 +84,8 @@ module Discourse
   # Cross site request forgery
   class CSRF < StandardError; end
 
+  class Deprecation < StandardError; end
+
   def self.filters
     @filters ||= [:latest, :unread, :new, :read, :posted, :bookmarks]
   end