Updated plugin to version 0.3.1

git-svn-id: https://plugins.svn.wordpress.org/author-customization/trunk@886076 b8457f37-d9ea-0310-8a92-e5e31aec5664
Removed screenshots from trunk

git-svn-id: https://plugins.svn.wordpress.org/author-customization/trunk@886080 b8457f37-d9ea-0310-8a92-e5e31aec5664