/**
  * Gets the given site prefernce
  *
  * @since 0.6
  */
 public static function get_preference($prefname, $defaultvalue = '')
 {
     $value = $defaultvalue;
     if (count(self::$siteprefs) == 0) {
         self::$siteprefs = CmsCache::get_instance()->call('CmsApplication::load_site_preferences');
     }
     if (isset(self::$siteprefs[$prefname])) {
         $value = self::$siteprefs[$prefname];
     }
     return $value;
 }