Tax ordering is lost on checkout

It would make sense if taxes were ordered according to their priority in the cart checkout, but they're not, and it seems there is no easy way to modify their order.

Actually taxes are correctly ordered until this call in "catalog/controller/checkout/cart.php" :
The array_multisort function gets rid of the initial ordering in case of equality on the sortering key (which here is the sort order as defined between total, subtotal, taxes, etc., and therefore is the same for all taxes).

Not really a bug fix, but here is a workaround.