To create a new roclet, you will need to create a constructor function
that wraps roclet, and then implement methods for
roclet_tags, roclet_process, roclet_output, and roclet_clean.
roclet(subclass, ...)roclet_output(x, results, base_path, ...)
roclet_tags(x)
roclet_process(x, parsed, base_path, global_options = list())
roclet_clean(x, base_path)