[Implemented] Auto !siren- when pulling someone over

[R.Fiets [CA]]

I am using TC lights and after I pulled someone over, I type once PG Up and Pg Dn to get siren and lights off. Though it's easiest thing to do, but I must say, I have no idea if people still see visual siren's on their screen.
Karak's idea could make it easier for people who "forgot" (or don't "care" if they active) their sirens on.
Anyway, I like that idea.
@Sadie bind it and wholaa, you may use it anytime you think, it has been dangerous place for traffic. And btw, if you type your bind for caution twice, it will be removed. No need for 2nd bind.