Ahodges/doc/relnotes20141021

@mhoeber , @catong , @srpearce please take a look -- anything else to add? 
@explorerleslie , @shnayder ?
Oh, OK. I didn't realize that you could click on a username and see all the contributions that user has made (and now that I know about it, I don't see it in the docs - I'll add it to the student-facing stuff). Maybe one of these?

When you mark a response to a question post as the correct answer, a "marked as answer" confirmation message that contains your username appears above the text of the response. When you click your username in the confirmation message, a list of your contributions to course discussions now appears correctly.

When you mark a response as a correct answer to a question, and then you click your username in the "marked as answer" confirmation message, a page that lists your contributions to the course discussions now opens correctly.