digineo/lettr — pull request #1 by dmke (2013-04-11 12:45:19+00:00)
Title: Adjust configuration to work with Rails 3.2

Since Rails 3.2 dropped support for `class_inheritable_accessor`, I've added a condition to use `class_attribute` instead (if available).

Since nothing inherits from `Lettr::Whitelist`, there is no semantic difference between both attribute accessor methods.