Triumphant Olympics End With Pride, Relief ATHENS, Greece - Efharisto! A nervous world learned the Greek word for thank you and repeated it endlessly at an astonishingly successful Athens Olympics that quelled fears, surprised skeptics and greatly honored the birthplace of the games.    Fireworks and spectacular lighting kicked off the closing ceremony Sunday night, a two-hour extravaganza of folk dancing and music in the Olympic tradition that summed up the glee and relief the games brought to Greece...