Working script for publicly verifiable selection.

Made a start on the docs but it's been canned.

  From: "Tim Lucas" <t.lucas@toolmantim.com>
  To: "Mike Bailey" <mike@bailey.net.au>
  Subject: Re: First cut - will send pull request tonight

  Ben Schwarz and Keith reckon just go with me running the simple script and
  Ben Schwarz witnessing it for fairness.

  Not imperially provable, but simple and sufficient.

  Hope you understand! Next time if you want to get involved ahead of time,
  and whomever it is wants to do the ballot, we should do something cooler.
  This was just a crazy idea to hack it together and give it a shot.