THREE AND A HALF STARS: Like several other Sin City BBQ pits, Billy???s is the sort of place where selective ordering can yield the sort of smoked meat likely to impress purists and locals alike, and while not every option is equal the same can be said of any place in America ??? it???s not like anyone is singing the praises of North Carolina Brisket, Texas Pulled Pork, or Kansas City sausage with