Model of Limiter that enforces saturations only
after they were violated without interruption during a certain
amount of time.
Switching from saturated to non saturated
mode has no lag.
Different lag can be set for upper and
lower saturations.
Saturated or not saturated initial state
can be selected, if a saturated initial state is selected then it
remain active until a change from saturated to not saturated state
is detected.