/**
  * Constructor. Loads the appropriate driver class based upon the argument provided
  *
  * @param object $db
  * @param string $driver
  * @return DatabaseManager
  */
 function DatabaseManager(&$db, $driver = 'mysql')
 {
     $path = dirname(__FILE__) . DIRECTORY_SEPARATOR . 'dbdrivers';
     return DatabaseManager::loadDriver($db, $path, $driver);
 }