Formats a filename for user display.  The main purpose of this
    function is to ensure that the filename can be displayed at all.  This
    will decode the filename to unicode if necessary in a way that it will
    not fail.  Optionally, it can shorten the filename to not include the
    full path to the filename.

    :param filename: formats a filename for UI display.  This will also convert
                     the filename into unicode without failing.
    :param shorten: this optionally shortens the filename to strip of the
                    path that leads up to it.

def format_filename(filename, shorten=False):
    """Formats a filename for user display.  The main purpose of this
    function is to ensure that the filename can be displayed at all.  This
    will decode the filename to unicode if necessary in a way that it will
    not fail.  Optionally, it can shorten the filename to not include the
    full path to the filename.

    :param filename: formats a filename for UI display.  This will also convert
                     the filename into unicode without failing.
    :param shorten: this optionally shortens the filename to strip of the
                    path that leads up to it.
    """
    if shorten:
        filename = os.path.basename(filename)
    return filename_to_ui(filename)