update referer version

git-svn-id: https://plugins.svn.wordpress.org/groupdocs-documents-annotation/trunk@802951 b8457f37-d9ea-0310-8a92-e5e31aec5664
updated readme file


git-svn-id: https://plugins.svn.wordpress.org/groupdocs-documents-annotation/trunk@804737 b8457f37-d9ea-0310-8a92-e5e31aec5664