Export extension to produce A4/letter pages with the slides and some lines to take notes.

It often good to be able to hand out hardcopies of the slides with some space next to them to take notes. It should not be too hard (especially once the pdf export extension works well :-)) to produce an export extension that puts 2 or 3 slides on one A4 or letter page with some horizontal lines next to the slides to take notes. This feature has been proposed by Marc Eberhard.