When a new active connection is created, it gets added at the
beginning of manager's list. This means that the list contains most
recently activated connections first. Since the list is doubly-linked,
it is possible to efficiently iterate in both directions, so the order
of the list is mostly a matter of convention.
I think it is preferable to have oldest active connections at the
beginning of the list; let's reverse the order.
In most places where the list is iterated, the order doesn't
matter. Where it does, use the *_prev() variant to maintain the old
iteration order.
