Issue #2076: Two indistinguishable events for different cases of working set reordering

Fix for #2076

With this, now both drag and drop reorder and the context menu sort methods trigger the same `workingSetSort` event and drag and drop uses it in a way that it doesn't redraw the DOM.

It would have been pretty easy to remove the `workingSetDisableAutoSorting` event and just use the `workingSetSort` event to cancel the automatic sorting, but since pull request #4437, save as can sometimes trigger a `workingSetSort` event, which would disable the automatic sort in some unwanted situations.

@peterflynn Could you take a look as this solution? I think this is what you wanted :)