"forgive" overdues when marking an item lost

"forgive" overdues when marking an item lost

New option for forgiving (as opposed to voiding) overdues on
a circ when marking the item lost:

When circ.forgive_overdue_on_lost is set, attempt to make a
payment of type "Forgive" on the transaction for the amount
of outstanding overdue billings.

Only outstanding bills of type 1 (Overdue materials) will
be paid, and only the first contiguous grouping. If the
system finds an outstanding billing of type other than 1,
it will pay what it has found up to that point.

circ.forgive_overdue_on_lost has priority over the "void"
version of the same setting, if both happen to be set.

Signed-off-by: Jeff Godin <jgodin@tadl.org>