mod/hotpot MDL-22726 fix importing of intructions from a Hot Potatoes quiz file into the Moodle question bank

MDL-20184 more efficient and accurate detection of missing nodes in xml tree when importing Hot Potatoes XML files to Moodle question bank / quiz module

MDL-20184 when importing questions from Hot Potatoes files to Moodle question-bank / Quiz module, the readquestions() function wil return "false", to signify an error, if no questions are detected in the import file

MDL-20185 detect zero, "0", as an answer for a gap in a JCloze when importing to the Moodle's question bank / Quiz module

fix for MDL-13174 : replace calls to html_entity_decode() with hotpot_charcode_to_utf8() because html_entity_decode is broken in PHP 4

where the correct responses on a JQuiz multiple choice question all have a score of 0%, the scores will be corrected to 100%

prevent backslashes being inserted before #-sign in HTML entities by converting html-entities to UTF-8 when importing from Hot Potatoes quizzes into Moodle 's standard Quiz module

Please test it. Thanks!

Please, test this is correct, thanks!

rename "get_hotpotatoes_xxx" functions to "hotpot_get_xxx";
rename "seed_hotpotatoes_RNG" function to "hotpot_seed_RNG";
initialize all $question objects using $this->defaultquestion (if possible);
fix decoding of ampersands in HP quiz readings

added "$question->usecase = 0;" for JMatch and JQuiz quizzes (other quizzes already set this property)

took out call by reference in an addslashes to fix warning reported at http://moodle.org/mod/forum/discuss.php?d=23288#110511.

capability auto-discovery!