This bug is meant to be an omnibus to encompass the different features of the Accounts Rewrite, but to break them down into smaller more easily testable parts that do not radically alter all at once.
*** Bug 6427 has been marked as a duplicate of this bug. ***
I'm not sure exactly where the account rewrite is in the development process, but please consider allowing any outstanding fine or fee credits to be refunded directly to the patron in addition to having them apply to future fines and fees. Lost item replacement costs that are later refunded can be in amounts larger than can be readily reduced by fines.