Order of earlyUpdate execution.
Given two systems, a system with a lower earlyUpdateOrder value will have
it's earlyUpdate() method called before another system's earlyUpdate()
method with a higher order value.
Order of lateUpdate execution.
Given two systems, a system with a lower lateUpdateOrder value will have
it's lateUpdate() method called before another system's lateUpdate()
method with a higher order value.