Update download links to 0.2.0 final!

OSX binaries are up, I will create the `juliareleases` PPA later today, and once @ihnorton packages his windows binaries (I'm sorry Isaiah, I promise I will get my build infrastructure to build windows eventually!) we can merge this.

Do we want to open a section for 0.3.0-prerelease nightlies now, or should we hold off for a bit?