5.2.9
Restricts input to numeric values when the answer is an integer in a descriptive question.
changed question_count:[empty string] to assume that the setting itself doesn't exist
Fixed the processing when TRUE or FALSE is specified as the value of true-false (so that even capital letters are judged correctly), changed to make an error when converting if a value other than true and false is specified.
Fixed a bug in judging correctness when there is only one correct choice in a multiple choice question.
