By Barry Moody GORGONA ISLAND, Italy (Reuters) - High on a hillside overlooking the azure sea on a small Mediterranean island, two brawny men toil under the sun in a vineyard that has just released a 50-euro ($66) wine destined for the tables of top restaurants. This is not an exclusive wine estate or secluded retreat for the rich, despite the tranquil beauty. It is, rather, the residence of men serving long sentences for some of Italy's most notorious and brutal crimes, on an island named after monstrous sisters in Greek mythology with snakes for hair. ...