Form editor update

- when a custom field is updated, the matching form field is now also updated
- ability to toggle "is_required" on First name & Last name
- fixed position of validation errors on segment selection, checkbox and radio
- fixed form subscription not working when using custom fields
- fixed sortable in segment selection after list update (add/remove)
- updated position of messages in form subscription

assets/js/src/public.js

@@ -20,10 +20,7 @@ function(
       $('form.mailpoet_form').each(function() {
         var form = $(this);
 
-        form.parsley({
-          errorsWrapper: '<p></p>',
-          errorTemplate: '<span></span>'
-        }).on('form:submit', function(parsley) {
+        form.parsley().on('form:submit', function(parsley) {
 
           var data = form.serializeObject() || {};