Slobodan Milosevic, the late “Butcher of the Balkans” who was a hero to many of his countrymen, is back in Kosovo, where a Serb-run theatre is staging a musical exploring the dichotomy. The “Slobodan Show” premieres Tuesday in Gracanica, a Serb enclave in Kosovo, whose population of 1.8 million is predominantly ethnic Albanian. All the cast…