Return a unicode version of string decoded using the file system encoding.

def to_unicode_from_fs(string):
    """
    Return a unicode version of string decoded using the file system encoding.
    """
    if not is_string(string): # string is a QString
        string = to_text_string(string.toUtf8(), 'utf-8')
    else:
        if is_binary_string(string):
            try:
                unic = string.decode(FS_ENCODING)
            except (UnicodeError, TypeError):
                pass
            else:
                return unic
    return string