Process Direct Debits; finAccountDirectDebit.CanCombine() Function added

The Payment Method indicates whether Payments can be combined for a Client. Previously, the User Interface was responsible for enforcing this setting in the Process Direct Debits wizard. Due to the addition of the Process Direct Debits HTML Widget, this has been moved to the Business Layer.

Therefore, finAccountDirectDebit.CanCombine() has been added, and the User Interface has been updated to refer to this Function. If the Direct Debit has been processed, or cannot be exported, this Function returns False. Otherwise, it will return the Payment Method setting "Combine with other Payments for the same 'Main' Client?"