UP-3717 - session timeout

I'm not sure I would go that far?   If you do, the uportal instance would be unusable.  As soon as the user logged in, the dialog would pop.   If they dismissed it, it would immediately appear again.   I've considered some other options (eg. sessionTimeout * 0.75, or sessionTimeout - SOME_MIN_VAL) but not thrilled with either of those approaches either.   Would either of those be preferable to basically locking up the portal though?