Update 3.17.6

New: Function Application.HasDeliverableCartItems.

Fix: Invoice no longer shows payment details when there are no payment methods.

Fix: When an administrator completed an order it would ask a 2nd time to complete.

Fix: Could not set default values for ServiceSchedule.Ocurrences.

Fix: When specifying attendee details via guest checkout the 1st attendee now defaults to "1st Attendee".