Remove comment for now
Introduce ChainedCookieJars module to allow chained cookie jars without duplicating code
Remove method_missing with deprecation warning; methods haven't been deprecated, they've been removed
Change name of new cookie jar since we're not upgrading to encrypted, just changing the way we sign
Use a constant like the other config options
Use UpgradeLegacySignedCookieJar if secret_key and secret_token are set, no need for the extra config option
Move ChainedCookieJars up to fix load order issue