By Lefteris Papadimas CORFU, Greece (Reuters) -Fire fighters battling a blaze on a ferry sailing from Greece to Italy discovered a survivor on the stern of the still burning vessel on Sunday, the Greek coast guard said, reviving hopes that other missing passengers could still be found alive. Rescuers managed to take at least 281 out of 292 passengers and crew to safety after the blaze broke out on the Italian-flagged Euroferry Olympia early on Friday, but 11 people are still missing, according to the coast guard and ferry operator. Firefighters have been trying for days to contain the fire and…