DA ‘guns’ for the little guy — Half of the gun scofflaws caught packing heat illegally in the city wriggle out of jail sentences or do only minimal time, despite a get-tough law that’s supposed to send them to prison for at least 3½ years. That’s according to legal papers filed Friday that accuse the Manhattan District Attorney’s Office of coddling pistol-loving celebs, including ex-Giant wide receiver Plaxico Burress, rapper Lil’ Wayne and rocker David Crosby, while cracking down on average Joes.