Changelog for json-autotype-0.2.1.0

-*-Changelog-*- 0.2.1 Oct 2014 * Added option to use it as a filter ('-' is accepted input name.) 0.2.0 Oct 2014 * First release to Hackage. * Handling of proper unions, and most examples. * Automatically tested on a wide range of example documents (see tests/) * Initial documentation in README.md. 0.1.0 July 2014 * First experiments uploaded to GitHub, and discussed to HackerSpace.SG.