API - Add modifyDateStart and modifyDateEnd to ListCustomers
Please add parity with other List* on the API.
ListOrders, ListProducts, and ListShipments all allow us to specify a range for the modify date. ListCustomers does not. It should. It would benefit both parties as anyone using the ListCustomers feature is likely requesting much more data than needed from your servers, since you aren't allowing us to limit the request to a narrow date range.