Guillermo del Toro has been telling monster stories for as long as he’s been making films. A romantic with keen appreciation for the macabre, his creations are things of strange beauty, haunting, poetic and unforgettable. It’s no wonder his earliest love was “Frankenstein,” first the Boris Karloff film, then the novel, which set him on a path to becoming a filmmaker. Don’t expect a by-the-letter adaptation of Mary Shelley’s immortal story, however. This “Frankenstein,” in theaters Friday and