Getting version 4.6.0 ready

git-svn-id: https://plugins.svn.wordpress.org/advanced-sidebar-menu/trunk@801758 b8457f37-d9ea-0310-8a92-e5e31aec5664
added pro link to readme.txt

git-svn-id: https://plugins.svn.wordpress.org/advanced-sidebar-menu/trunk@801761 b8457f37-d9ea-0310-8a92-e5e31aec5664