Some improvements to the dashboard activity widget:

* Use the correct background color for unapproved comments.
* Use the sale box-shadow style instead of a border between rows so the orange border is uninterrupted between multiple pending comments.

See #25858.


Built from https://develop.svn.wordpress.org/trunk@26297


git-svn-id: http://core.svn.wordpress.org/trunk@26202 1a063a9b-81f0-0310-95a4-ce76da25c4cd