Recalculate order adjustments item quantity change

When doing adjustment recalculation we should probably always pass the
adjustable object. That way we can be sure the amount will be computed
over the current adjustable objects. Otherwise it might grab the
adjustable from the database which might not have the totals persisted
we need just yet.

Therefore this gives us speed, no need to hit the database again, and
accuracy as it will alwyas compute values over the amount we expected.
No need to choose best promotion if adjustment_total is 0