Painkiller, a hip Lower Eastside tiki den, is the creation of the crew behind Brooklyn’s Dutch Kills, Giuseppe Gonzalez and Richard Boccato. The bar merges the usual tiki kitsch with a vibe that’s pure New York: the interior is a collage of urban graffiti, bamboo-clad walls and Polynesian masks; the cocktails may be served in pineapple cups and coconut…