Add $class->is(...) (shorthand for isa)

  Made deeper hierarchy to make this work and because...

            _.-^^---....,,--
        _--                  --_
        <                        >)
        |                         |
        \._                   _./
            ```--. . , ; .--'''
                  | |   |
              .-=||  | |=-.
              `-=#$%&%$#=-'
                  | ;  :|
        _____.,-#%&$@%#&#~,._____

        mst wins: unixtality