Sometimes you come into a sequel standing on the shoulders of giants. Think Richard Lester’s SUPERMAN II or James Cameron’s ALIENS. With THE SUICIDE SQUAD, James Gunn finds himself in the unenviable position of standing in the hole dug by the previous – bafflingly Oscar-winning – film. Happily, as it turns out, that hole isn’t a grave. Ayer’s for-want-of-a-better-word “vision” was dark,…