* Add classes like `.site` and `.site-content` in addition to the set of IDs already present, making things much better for child themes to have more than one generic element like `nav` inside the content container.
* Bump JS version after selector change.
* Move `image-attachment` to `post_class()` output
More exhaustive notes in the ticket on each id and class change.
git-svn-id: https://develop.svn.wordpress.org/trunk@21404 602fd350-edb4-49c9-b593-d223f7449a82