#485 - Fix some broken tests and update javadocs on some services
#485 - Remove CustomerPayment from OrderPayment, add some new methods for transactions on order payment
#485 - Consolidate checkout into 1 method and also make checkout thread safe. Checkout will now fail if 2 threads attempt to check out the same order or if the order has already been submitted
#485 - First draft at an activity in the checkout workflow that confirms outstanding payment transactions as well as ensures that enough payment has been collected for the order
#485 - Add currency to the translation from the Broadleaf order to a payment request
#485 - Move the payment gateway configuration into common so that the framework can get a handle to it
#485 - Add some additional docs to OrderStatus