Implement hook_node_type()

As the project modules use Drupal variables with a name containing a content type ID, they should implement hook_node_type to have code similar to

/**
 * Implementation of hook_node_type().
 */
function basic_metatags_node_type() {
  switch ($op){
    case 'delete':
      variable_del('basic_metatags_user_teaser_'. $info->type);
      break;
    case 'update':
      if (!empty($info->old_type) && $info->old_type != $info->type) {
        $setting = variable_get('basic_metatags_user_teaser_' . $info->old_type, FALSE);
        variable_del('basic_metatags_user_teaser_' . $info->old_type);
        variable_set('basic_metatags_user_teaser_' . $info->type, $setting);
      }
      break;
  }
}