Created Unassigned: Unobtrusive Ajax doesn't execute error handlers [1506]

Porting from https://aspnet.codeplex.com/workitem/9742:

In line 98 of jquery.unobtrusive-ajax.js, the script gets the error handler from the data-ajax-failure attribute but then doesn't actually execute it.

Line currently looks like:
error: getFunction(element.getAttribute("data-ajax-failure"), ["xhr", "status", "error"])

When it should really be:
error: function() {
getFunction(element.getAttribute("data-ajax-failure"), ["xhr", "status", "error"]).apply(this, arguments);
}