DOCBOOK: Slides proposal/RFE

In the slides 2.0 distribution, only the root element slides and the
element section contains a speakernotes element.

Usually I would prefere notes to be associated with a specific foil.

I would therefore propose to change the foil element to:

<!ELEMENT foil (foilinfo?, title, subtitle?, titleabbrev?, speakernotes?,
                (%divcomponent.mix;)+)>

Regards

Jens