Node title labels are not translated in forms

This is a follow up for the title label issue mentioned in http://drupal.org/node/1550678

In order to have a translated node title label, this:

    // Title label.
    if ($key == 'title' && $entity_type == 'node') {
      $node_type = node_type_get_type($entity);
      $field['title'] = $node_type->title_label;
    }

needs to be replaced with:

    // Title label.
    if ($key == 'title' && $entity_type == 'node') {
      $node_type = node_type_get_type($entity);
      $field['title'] = function_exists('i18n_node_translate_type') ? i18n_node_translate_type($node_type->type, 'title_label') : $node_type->title_label;
    }

I think this also applies to the 2.x branch.