Add different headers to the ebooks
Add different headers to the ebooks

- 'Vorspann' to the first level1 in the frontmatter
- 'Nachspann' to the first level1 in the rearmatter
- 'ohne Überschrift' to all level1 and level2 without a h1 or a h2
- a br to p[@class='preceedingemptyline']
- a *** + br to p[@class='preceedingseparator']

sbsdev/daisyproducer,sbsdev/daisyproducer,sbsdev/daisyproducer,sbsdev/daisyproducer