LP 1198465: Add code for adjustment payments

LP 1198465: Add code for adjustment payments

This new payment type complements the current void logic that flags
bills as voided.

This new payment type is needed because the current way that Evergreen
voids bills requires that all voids happen in the same increment as the
bills themselves.  This prevents voiding of a partial bill or a bill
that has had a partial payment applied.

This commit also adds the org. unit setting types for the conditional
negative balances enhancements:

bill.prohibit_negative_balance_default
bill.prohibit_negative_balance_on_overdues
bill.prohibit_negative_balance_on_lost
bill.negative_balance_interval_default
bill.negative_balance_interval_on_overdues
bill.negative_balance_interval_on_lost

Finally, create a helper function for checking intervals along the way,
and a handy little subroutine to void all bills of a given type on a
circulation transaction.

Signed-off-by: Dan Wells <dbw2@calvin.edu>