Use jQuery params to create URL strings.

[jolting]

jQuery allows you to encode objects into url strings very easily and it's clean.
This will improve readability.

For example in quiz.js the URL generation is ugly.
function linkToQuizFromJSON(url) {
return url.attr("protocol") + "://" + url.attr("host") + url.attr("directory") + "quiz.html" +
"?seed" + seed.toString(16) +
"&jsonString" + url.param("numQuestions") +
extraParams;
}

wouldn't it be better to write
var params = { 'seed' : seed,
'numQuestions' : numQuestions,
...
};
var str = jQuery.param( params );

https://foo.cs.ucsb.edu/seriousjs/index.php/JQuery:URL_Parameters