Add an asset_host accessor for consistency.

actionpack/lib/action_controller/base.rb

@@ -67,8 +67,7 @@ def self.subclasses
       @subclasses ||= []
     end
 
-    # TODO Move this to the appropriate module
-    config_accessor :asset_path
+    config_accessor :asset_host, :asset_path
 
     ActiveSupport.run_load_hooks(:action_controller, self)
   end