A Comp should be per Attendee, not per User Account

[thoel]

Every "comp" is issued to a particular attendee, and should be managed that way. When a comp is issued to a youth attendee, it is not supposed to be shared by the family. Currently, comps are implemented as an add-on to the Transactions page, and those are done per user account. It might be worth creating a separate table for comps, and a separate user interface page, so that these can properly be done per attendee.