FEATURE: Accumulative Order Balance

Now you can quickly see order balance totals by customer, in one view.

Added new Total Orders Balance column to customer list page in admin console.
1. Included a store setting to exclude declined orders from the total.
2. Total value is stored in TotalOrdersBalance field on customer object to keep us from having to calculate on the fly.
3. Totals are recalculated for the specific customer for an order when the order status is changed or payment is applied.
4. Totals are also recalculated for all customers with declined orders when the store setting is changed.