Miscellaneous improvements to Quiz.html

[apia46]

Sorry about how messy that was last time. Renamed variables: "everything" -> "allQuizzes" "thing" -> "quizName" "inf" -> "quizData" "first" -> "querySide" "ansIx" -> "queryIx" Changed array shuffle to use ShuffleFisherYates function instead of manually shuffling Fixed bug where the correct item group of the question was not identified in boundary cases Fixed bug where it was possible to have two visibly identical answers where one is correct and one isn't, if two different items have the same answer(s)