Every Sept. 1, readers of “Thirty-Three Cecils” gather at a neighborhood pub to remember two men who never existed — and to celebrate the strange way a novel became part of a city. BINGHAMTON, N.Y. — On Sept. 1, people make their way to the Belmar Pub, order drinks and raise their glasses to two men who died years ago. There is only one complication. Neither man ever existed. They are characters from Thirty-Three Cecils, a novel by Everett De Morier whose fictional world is r