change variables, update version

git-svn-id: https://plugins.svn.wordpress.org/timespan/trunk@1002666 b8457f37-d9ea-0310-8a92-e5e31aec5664
update readme

git-svn-id: https://plugins.svn.wordpress.org/timespan/trunk@1002671 b8457f37-d9ea-0310-8a92-e5e31aec5664