CookieStore does not get passed config settings

Followup to #2001 Rails 2.3 does not obey config.action_controller.session_store

"Lazy evaluate ActionController session store middleware class to pickup custom plugin session stores" http://github.com/rails/rails/co... made MiddlewareStack accept a Proc as a class name.

It should also accept injected arguments as Procs so that arguments can be evaluated lazily.

This fixes the issue mentioned in the comments of #2001 Rails 2.3 does not obey config.action_controller.session_store that stops the application from starting up when CookieStore does not get passed the options configured in config.action_controller.session