If there’s one thing to take from “Butt Boy,” director Tyler Cornack‘s dark, stomach-churning tale of a serial killer who uses his anus as his weapon of choice (yes, really), it’s that playing a silly idea as straight horror can work. This kooky and wildly weird movie will exceed the needs of its very, very small niche audience: those fans of deranged midnight cult flicks and deadpan, exceedingly ver mais...