Update to include latest version of wordpress.

git-svn-id: https://plugins.svn.wordpress.org/widget-posts-by-category/trunk@823514 b8457f37-d9ea-0310-8a92-e5e31aec5664
Update to 3.8

git-svn-id: https://plugins.svn.wordpress.org/widget-posts-by-category/trunk@823517 b8457f37-d9ea-0310-8a92-e5e31aec5664