add a test for req.seesion.cookie.maxAge changed to large value
remove req.session.cookie.hasLongExpires because YAGNI

It's not only not needed, but also cause problems.
https://github.com/senchalabs/connect/issues/859
Merge pull request #870 from undoZen/master

remove req.session.cookie.hasLongExpires because YAGNI