Bug fix: open to details page not handled; tested to 4.0

git-svn-id: https://plugins.svn.wordpress.org/my-calendar/trunk@979551 b8457f37-d9ea-0310-8a92-e5e31aec5664
Update version numbers

git-svn-id: https://plugins.svn.wordpress.org/my-calendar/trunk@979553 b8457f37-d9ea-0310-8a92-e5e31aec5664
Set stable tag to 2.3.13

git-svn-id: https://plugins.svn.wordpress.org/my-calendar/trunk@979571 b8457f37-d9ea-0310-8a92-e5e31aec5664