In the past decade, Jane Austen's "Pride and Prejudice" has been fodder for something like 200 adaptations, mutations and spinoffs, and still it is not a truth universally acknowledged that enough is enough. Curtis Sittenfeld, perhaps best known for her first novel, "Prep," and notorious for her third one, "American Wife" (based on the life of Laura Bush), now joins in with "Eligible" a highly entertaining romp of a novel set in 2013 in Cincinnati.