Sorting problem where table variables could change according to sort values

git-svn-id: https://plugins.svn.wordpress.org/cformstable/trunk@989378 b8457f37-d9ea-0310-8a92-e5e31aec5664
Clarified instructions

git-svn-id: https://plugins.svn.wordpress.org/cformstable/trunk@989383 b8457f37-d9ea-0310-8a92-e5e31aec5664