update 6.0.0

git-svn-id: https://plugins.svn.wordpress.org/dx-seo-tool/trunk@769786 b8457f37-d9ea-0310-8a92-e5e31aec5664
update

git-svn-id: https://plugins.svn.wordpress.org/dx-seo-tool/trunk@769788 b8457f37-d9ea-0310-8a92-e5e31aec5664