Answering question is now always required to avoid premature ending of the quiz

git-svn-id: https://plugins.svn.wordpress.org/chained-quiz/trunk@861045 b8457f37-d9ea-0310-8a92-e5e31aec5664
Fixed problems with processing open-end questions

git-svn-id: https://plugins.svn.wordpress.org/chained-quiz/trunk@861901 b8457f37-d9ea-0310-8a92-e5e31aec5664