Dropwizard 0.6.2 documentation

This PR adds the Dropwizard 0.6.2 documentation and Maven sites to the `gh-pages` branch into the directory `0.6.2`.

The docs have been generated from the `v0.6.2` tag, the URL will be http://dropwizard.github.io/dropwizard/0.6.2 for the documentation and http://dropwizard.github.io/dropwizard/0.6.2/maven for the Maven sites. A fully rendered GH page can be viewed at http://joschi.github.io/dropwizard/0.6.2/ (until it's available under the canonical URL).

This will close #529.