add feature to extend preclusive zone alarm state by x frames

Totaly new to git/githup so in all probability this will not be usable as-is. Please provide  feedback on how to correctly propose a change.
Here's the problem I'm trying to solve: After sudden change in lighting, my cameras tak a few moments to adjust auto-exposure. Combined with gradual image blending, I end up with a slowly shrinking alarmed area that will result in a false alarm.
I can easily define a preclusive zone that will trigger on the change in lighting, but I need to keep the preclusive alarm active for a couple of frames to avoid the false alarms.
I Added a column for the number of frames to keep a preclusive zone in alerted state after the alarm would normaly have gone inactive to the Zones Table, Added that column to the zone definition screen in classic and flat skin and changed motion detection to implement this change.
Thanks for any feedback!