Italian is not just a language, but also a shared vision of the world, Foreign Minister Antonio Tajani told the first Conference of Italofonia at the Raphael-designed Villa Madama in Rome Tuesday.     "We are at the heart of Italianness," Tajani, who is also deputy premier said in opening the conference, pointing to Raphael's architectural work as the symbol of a tradition that speaks to the world.     For the minister, Italofonia "is not just being Italian citizens, but having a shared vision,