Bug #0001133: One-step Checkout
1. new ShippingSubTotal calculated field in order to display shipping cost + insurance fee
2. notice fixed during shipping limitation calculation on empty order
3. parameter "payment_type_id" is now supported in all payment gateway related tags
4. tag ord_PrintTotals changed to allow displaying of an order discount
5. calculated fields were missing in ItemSQLs of payment type
6. added ability to load first enabled payment type, that has specific payment gateway name in settings
MINC-81