+ # credit remaining time if any of these are true:
+ # - unused_credit => 1 was passed (this happens when canceling a package
+ # for a package change when unused_credit_change is set)
+ # - no unused_credit option, and there is a cancel reason, and the cancel
+ # reason says to credit the package
+ # - no unused_credit option, and the package definition says to credit the
+ # package on cancellation