Developer - Gateway "_capture" function should support "pending" response
The _Capture function currently only supports a "success" or "denied" response which is fine when the payment gateway is real time but certain payment methods (eg. Direct Debit) do not immediately return a 'success'.
The function should either support a "pending" state or allow a null response so that the _capture occurs transparently so that neither false "success" or "failure" emails are not generated and in the case of a "success" renewals are not automatically processed when the payment may later fail.
A "pending" state would require extract logic within WHMCS to handle subsequent switches from "pending" to "success" (paid) but would probably be the most flexible. If this is not possible a "null" response that triggers nothing would allow a callback to later trigger the addition of the transaction and auto renew domains, etc.