Adding contextual DOM information to returned observable information

So, we're big fans of Knockout-Validation on our web app.

Normally, we just use inline validation, but we have a pretty beefy form that we want to enhance with some extra information (like an error summary, and showing where errors are on the page).

It would help to have contextual information about the error's validationElement. Something like this:

ko.bindingHandlers['validationElement'] = {
    update: function (element, valueAccessor, allBindingsAccessor) {
        ...
        obsv.validationElement = element;

With that change, you can then get this information out of the errors foreach loop:

        validator.errors.forEach(function(item) {
            if(!item.error()) {
                return;
            }
            console.log(item.validationElement); // Returns dom node used as validationElement.
        });

Would something like this be useful as a PR for other folks?

Start at the validationElement binding handler shown in the issue and trace how its observable validation information is returned through validator.errors. Expose the validation element on each returned item, then verify that an errors foreach loop can read item.validationElement as the DOM node used for validation.