Packed behind security barriers, scorched by the sun and pelted by rain, they are the real stars of the Cannes film festival - the intrepid autograph hunters. The fans on the front line of the world's largest cinema showcase, perched on stepladders across from the famous red carpet steps, are ecstatic about all the celebrities and the glamour. "I'm living my dream ... There's no one happier than I am. It's been building up since when I was six or seven," said Martine Santoro, 61, who watched the images from Cannes when she was a child in Paris and vowed to get there one day in person. true A toy piano rigged up on the front of Santoro's stepladder is her homage to this year's festival jury president, "The Piano" director Jane Campion. The instrument caught Campion's eye on opening night and she came over to sign an autograph, as did Nicole Kidman, there to promote her starring role in "Grace of Monaco". As the mov