Lightspeed R-series: Sale Line Image per AdVision eCommerce

Extension is activated on the open sale (register) interface of Lightspeed Retail R-series admin (https://us.merchantos.com/register.php). As sale lines are added to the sale, a call is made to the logged in user's Retail account API to get the sale line item's primary image. That image is then displayed as a thumbnail in the sale line next to the item's description.