> |$(event.currentTarget).data('annotation')| can be called from the
onAnchorMouseOver.
> I'm not sure it's violating clean abstraction to expect that we can
call this on whatever
> |event.currentTarget| is, and get the annotation data.

I'm pretty sure that does not work with image annotations.
(They need to do some interaction with Annotorious to get back the
corresponding annotations.)

> Either that or we should implement a custom event type, and have the
> anchor implementation emit that with the annotation(s) attached.
>

How about I just put both the `annotations` and the `highlightType`
fields inside the existing event, so that the event object is the only
thing passed?