Given a list of option strings this joins them in the most appropriate
    way and returns them in the form ``(formatted_string,
    any_prefix_is_slash)`` where the second item in the tuple is a flag that
    indicates if any of the option prefixes was a slash.

def join_options(options):
    """Given a list of option strings this joins them in the most appropriate
    way and returns them in the form ``(formatted_string,
    any_prefix_is_slash)`` where the second item in the tuple is a flag that
    indicates if any of the option prefixes was a slash.
    """
    rv = []
    any_prefix_is_slash = False
    for opt in options:
        prefix = split_opt(opt)[0]
        if prefix == '/':
            any_prefix_is_slash = True
        rv.append((len(prefix), opt))

    rv.sort(key=lambda x: x[0])

    rv = ', '.join(x[1] for x in rv)
    return rv, any_prefix_is_slash