Superseded by http://cheesehead-techblog.blogspot.com/2015/10/cac-on-firefox-using-ubuntu-1504.html
Adding a CAC Card reader and using a CAC card with Ubuntu used to be bloody hard. Getting the hardware recognized, getting the add-ons to Firefox and Evolution, installing the certificates, what a pain!
Well, I tried agin, using the Ubuntu help center instructions at https://help.ubuntu.com/community/CommonAccessCard
Result: I can log into AKO using my CAC Card! After four years of hoping. Hooray!