Order-3 and order-4 use almost the same code. With lazy exclusions it was
exactly the same. But for full exclusions is not.

The problem is that when updating we can't be sure that the stored pointer
points where it should to (as it did with lazy exclusions). So we have to
read the whole linked list. This is done for order-2 and order-3. However
order-4 is the highest order used, so it doesn't use exclusion, therefore
it uses the same code as with lazy exclusions.

So if you want to use higher orders remember that the code to use should
be the one for order-3 because it updates correctly when exclusions are
being used. and use the order-4 code for the highest order.

                                   Arturo Campos (arturo-campos@mixmail.com)
					        http://www.arturocampos.com