Version 3.5.9 - Fixed bug that was causing loss of data in some specific cases

git-svn-id: https://plugins.svn.wordpress.org/wp-slimstat/trunk@890094 b8457f37-d9ea-0310-8a92-e5e31aec5664
Version 3.5.9 - Updating readme.txt

git-svn-id: https://plugins.svn.wordpress.org/wp-slimstat/trunk@890095 b8457f37-d9ea-0310-8a92-e5e31aec5664