Add option to maintain payment status

I've now added this feature because I required it :)

Here's the code to add for a proper management of payment status:

1. Add these lines to commerce_directdebit.module:

/**
 * Implements hook_menu().
 */
function commerce_directdebit_menu() {
  $items = array();

  // Add a menu item for capturing authorizations.
  $items['admin/commerce/orders/%commerce_order/payment/%commerce_payment_transaction/directdebit-confirm'] = array(
    'title' => 'Confirm payment',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('commerce_directdebit_confirm_form', 3, 5),
    'access callback' => 'commerce_directdebit_transaction_confirm_access',
    'access arguments' => array(3, 5),
    'type' => MENU_DEFAULT_LOCAL_TASK,
    'context' => MENU_CONTEXT_INLINE,
    'weight' => 2,
    'file' => 'includes/commerce_directdebit.admin.inc',
  );

  return $items;
}

/**
 * Access callback function to limit use to non-completed direct debit transactions.
 */
function commerce_directdebit_transaction_confirm_access($order, $transaction = NULL, $account = NULL) {
  $access = commerce_payment_transaction_access('update', $transaction, $account);
  if ($access && $transaction) {
    if (!in_array($transaction->payment_method, array('commerce_directdebit', 'commerce_directdebit_sepa'))) {
      $access = FALSE;
    }
    else if ($transaction->status == COMMERCE_PAYMENT_STATUS_SUCCESS) {
      $access = FALSE;
    }
  }
  return $access;
}

2. Add the attached "commerce_directdebit.admin.inc" to the "includes" directory.

PS: It would be very very cool, if you could add DROWL.de to the list of sponsors on the module page perhaps, if the new features helped you, and you also think this would be fair. If not, it's also okay for us. Thanks a lot in advance!

Thanks a lot to the maintainers of commerce_bank_transfer.module, whose code was a very good basis for further development of this functionality.