Returns all customers who have not yet been marked as synchronized, or have been marked, but have since changed or been updated in some way.
The field customers is populated with an array of zero or more CustomerBean objects, one for each unsynchronized customer.
One or more failure fields will be populated with a failure object (will contain a non-null reference) indicating the nature of the failure, with relevant information.
|AccessDeniedFailure||The username or password was incorrect, or lacked the right to complete this function.|
|ValidationFailure||One or more fields contained invalid values.|