Katie Couric must be ready to ring the necks of Jackie Mason and Raoul Felder after their insulting assessment of her performance on “The CBS Evening News.” In their new book, “Schmucks: Our Favorite Fakes, Frauds, Lowlifes, Liars . . .” the acid-tongued comic and celebrity divorce lawyer write of the ratings-challenged anchor: “Perky goes a long way in this country, but one place it doesn’t belong is behind the news desk. Walter Cronkite, Tom Brokaw, even Barbara Walters – these newscasters had and have gravitas. They deliver the news. They do not perch, one cheek on, the other off, the anchor desk. They do not crinkle their eyes or wear glittery lipstick . . . Forgive us, we don’t want to hear about World War III from anyone named ‘Katie.’ ” Matthew Hiltzig, a spokesman for Couric, responded by joking to Page Six: “Gee, are those two schmendricks [jerks] still alive?”