Evil Dead: The Musical officially came to life this month at New World Stages; we caught the show in previews, in a house packed with Evil Dead fans who reveled in every campy moment. The first two rows are given Gallagheresque ponchos and by evening’s end the audience in this so-called “splatter zone” is bathed in enough blood to run the Red Cross for a month. (If you’re grossed out by the amount of blood......