sortupdate event doesn't fire when removing a single remaining item in connected lists

[neonwired]

When using connected lists if you remove a single remaining item from one list, leaving no items in that list, the sortupdate event isn't fired, it's only fired by the other connected lists.

Obviously you can listener for the event on both lists but this is messy as you'll get two events for every item move. It should really fire on both if there are connected lists.

[lukasoppermann]

Hmm, is it fired before on the list, the item is removed from? Maybe we should have separate events for item removed and item added, so you actually know what happend. But maybe thats an overkill. Feel free to send a PR to fix this.