Cannes hailed the premiere of the Australian director's interpretation of the Shakespeare tragedy, the final film to screen in competition at the festival, which concludes Sunday. The film, among the most eagerly awaited at Cannes, is a grimly visceral adaptation of "Macbeth," shot partly in Scotland, striking in the bleak beauty of its earthy violence. In Kurzel's film, the Macbeths are less an ambitious, power-hungry pair than a desperate, childless couple in freefall. "Macbeth," which the Weinstein Co.