Fix mouseout on nested elements

The `mouseout` event triggers for nested children of a target element. This causes tooltips to flicker if they're attached to an element with nested elements eg. `no_translate`.

This fix uses the jquery event listener `mouseleave` to stop propagation of the children mouse out pointer events.

@xzyfer @joshamos Anything I haven't thought about that this could potentially break?
Any reason `mouseout click` couldn't have just become `mouseleave click `?

Is there some jquery weirdness around mouseleave?