Sylvia/docs/relnotes 7 30

@lamagnifica @mhoeber Please review. There's some back-and-forth about the PR with the Analytics changes in the Release HipChat room; I'll keep watching it and remove this info if necessary.
Maybe something like this, if you want workflow in there, tear apart as you see fit: "In Studio, new publishing capabilities will make it easier for course authors to edit and publish content. We've simplified the publishing workflow and added clear indications for publish/release status, so you'll always know whether students can see your content."