hide errors caused by malformed html

git-svn-id: https://plugins.svn.wordpress.org/quotable/trunk@898175 b8457f37-d9ea-0310-8a92-e5e31aec5664
clarify changelog

git-svn-id: https://plugins.svn.wordpress.org/quotable/trunk@898176 b8457f37-d9ea-0310-8a92-e5e31aec5664