Release notes for 7-23-2014

@mhoeber @lamagnifica Please review. I only found three items to include in the notes this week.

Note that I have an internal comment on line 26.

Draft at http://draft-release-notes-7-23.readthedocs.org/en/latest/07-23-2014.html
It's not really an explanation. It's an alert to the safety net of being able to change the display name if needed. (This was always provided under the Organization Name field, but missed for Course Display Name.)