Upgrade effect Membeship expiration dates instead of beginning date

An upgrade needs to affect the expiration date. If someone upgrades from a 30 day membership to 90 day membership it should add 90 days onto the expiration date, not give them 90 days total instead of 30, that is what the customer is expecting, they just purchased 90 more days. Also the upgrade feature needs moved out of the table header and below the renew feature so they have clear a choice.