public static function registerZend()
 {
     if (self::$zendLoaded) {
         return;
     }
     if (!class_exists('Zend_Loader_Autoloader')) {
         $path = sgConfiguration::get('settings.ZendAuthPlugin.zend_lib_path');
         set_include_path($path . PATH_SEPARATOR . get_include_path());
         require_once $path . '/Zend/Loader/Autoloader.php';
     }
     Zend_Loader_Autoloader::getInstance();
     self::$zendLoaded = true;
 }