clean up Ordering. method docstrings

--HG--
extra : amend_source : 54059dbc86ddb081936b5e850b150adca9fcf33a
clean up Shuffle docstrings
clean up NonAtomicOrdering docstrings
clean up CompleteCounterbalance docstring
clean up Sorted docstrings
clean up LatinSquare docstrings
clean up latin square function docstrings
don't add parentheses after callables in docs
use namedtuple for return values representing new IVs in order module