This change allows form elements to be overridden with a mustache template.
The template can even listen for form validation errors and supply the JS to
change the look of the form element when there is/isn't a validation error.
Initial support is for all core form elements including:
text, select, selectyesno and checkboxes, groups, dateselector, datetimeselector,
autocomplete, modvisible, advcheckbox, button, duration, filemanager, filepicker, editor, static, grading,
warning, textarea, password, url, submit, questioncategory, recaptcha.
Part of MDL-55071
When nodes are added to the dom, they may need to be re-processed by a JS based
filter. To do this we need to trigger the legacy YUI event filter-content-updated.
To make this easier I added some wrappers to template that will insert the node, run any
JS and trigger the event.
I also changed existing yui code to call the amd function to trigger the event. This way
all jquery and yui listeners will always be notified.