Update to the readme for version 1.2.5

git-svn-id: https://plugins.svn.wordpress.org/admin-bar-button/trunk@900394 b8457f37-d9ea-0310-8a92-e5e31aec5664
Creation of version 1.2.5

git-svn-id: https://plugins.svn.wordpress.org/admin-bar-button/trunk@900396 b8457f37-d9ea-0310-8a92-e5e31aec5664