Luis H. Rodriguez, an I.B.M. executive, with his children, Alec, 5, and Evia, 2, often works from his home or on the road.Credit...Joyce Dopkeen/The New York Times SOMERS, N.Y. — It’s every worker’s dream: take as much vacation time as you want, on short notice, and don’t worry about your boss calling you on it. Cut out early, make it a long weekend, string two weeks together — as you like. No nee