Uploading 1.0.0b13.

git-svn-id: https://plugins.svn.wordpress.org/task-scheduler/trunk@976293 b8457f37-d9ea-0310-8a92-e5e31aec5664
Marked 1.0.0b13 as stable.

git-svn-id: https://plugins.svn.wordpress.org/task-scheduler/trunk@976296 b8457f37-d9ea-0310-8a92-e5e31aec5664