Rails/Rack inconsistency about `:expires_after`/`:expires` cookie option.

What's more -- Rack seems to expect the :expires option as a Time object. I keep getting can't clone Fixnum (TypeError) because I have :expires in my environment.rb set to a number of seconds in the future... Setting the config.action_controller.session = { :expires => '...' } to a Time object doesn't really make sense, does it?

Fixed in this commit

Also this monkeypatch works for me (until Rails is fixed)

+1 :)

Forgot to mention here's pending rails pull request with fix