Export only serves first row of result set

When exporting any contacts the resulting csv always holds one single line besides the header.

Hunting the reason I saw that CRM/Export/BAO/Export.php's exportComponents method uitilizes CRM_Core_DAO::executeUnbufferedQuery($limitQuery) and after that calls $dao->fetch() which won't work with unbuffered mysql results.

I won't offer a patch here because we don't suffer from too less memory and I decided just to call executeQuery() than to fetch results from mysql...