Provide a configurable flag (:flag_cookies_as_secure) so that users of Rack-SSL can disable the flag_cookies_as_secure functionality.

Provide a configurable flag (:flag_cookies_as_secure) so that users of Rack-SSL can disable the flag_cookies_as_secure functionality. This is useful for rails apps that require SSL, but whose cookies need to be readable by third party systems that do not force SSL.

I reverse-merged the `options` hash with `{:flag_cookies_as_secure => true}` so that the default behavior would remain unchanged.