integrate deedpoll to standardize common identifiers

We should also settle on either `i` or `idx` for loop variables. (My vote is for the latter.)

But this is only a problem if we change the implementation code that uses `fnArity` to describe the arity of the function and `arity` as a reference to the function in scope.  There is no great reason to make this change except to [annoy Ralph Waldo Emerson][rwe]: "_A foolish consistency is the hobgoblin of little minds_."

I think that's why I'm resisting tools like deedpool.  It's not that I don't think they have value; but I want tools to help me write the way I want, not to dictate to me the way I _should_ want.  And I do recognize that this is a little silly on any team project, but it's still my gut reaction.

  [rwe]: http://www.bartleby.com/100/420.47.html