- Simplified dragHover "plugin" by counting children instead of storing them.
Counting children fixes Firefox 57+ bug (to be found or filed) that causes
text object of input element to produce drag events
- Removed multimethod since it's no longer used anywhere
- Firefox 57+ appears not to trigger a change event when the `files` field is modified,
which prevented uploads from occuring. This commit triggers a change event manually
and doesn't impact the functioning of other browsers.