FOURTEEN miles off the tail end of Andros Island in the Bahamas lies the island called Dark Bahama&mdash;which, says the guide book, is a natural paradise.<br />Day and night the golden sand beaches, the calm inlets, the palms, the cats-tail trees, are bathed in sunlight and moonshine&mdash;especially moonshine. It is always summer except when a half-hurricane strikes in the season and the drunks have another excuse for nerve troubles.