EllisLab/CodeIgniter — pull request #2118 by onlilove (2013-01-04 13:17:46+00:00)
Title: Update system/libraries/Form_validation.php

if ($val !== '')
{
//For more custom, delete this "\n"
// now you can do this :
// validation_errors("

","

\n");
// or this :
// validation_errors("

","

");
$str .= $prefix.$val.$suffix;
}