Move all styling into stylesheet.css
Make a new high-resolution cover image

cover-hires.jpg is a retouched version of
http://ia600308.us.archive.org/BookReader/BookReaderImages.php?zip=/6/items/stagestosaturnte00bilsrich/stagestosaturnte00bilsrich_jp2.zip&file=stagestosaturnte00bilsrich_jp2/stagestosaturnte00bilsrich_0001.jp2

cover.jpg is a downscaled version for EPUB
Check for main.html before creating the EPUB
Fix typos in chapter 5