Cleaned up the failed order logic to remove cart association before user is given a choice to cancel or retry the order - this means the order is disassociated from the session cart even if the user exits the page without selecting a choice. The cart is associated once again if the order clicks to retry and it doesnt contain specific paypal error codes. Cleaned up the shipping selector logic for the estimate shipping and shipping stage; the tier value for an order is now saved against the order record as an array value (postgres). This means a quicker ajax call for the collection of available shippings and allows the user to view other shipping options in the same country if one has already been selected at the estimate shipping.