0.17 fix http://wordpress.org/support/topic/php-error-on-activation-2?replies=4

git-svn-id: https://plugins.svn.wordpress.org/hook-sniffer/trunk@921514 b8457f37-d9ea-0310-8a92-e5e31aec5664
Fix readme.txt, Add changelog

git-svn-id: https://plugins.svn.wordpress.org/hook-sniffer/trunk@921516 b8457f37-d9ea-0310-8a92-e5e31aec5664