'use strict'; be safe
Use archive.org's EPUB as a starting point

Extract stagestosaturnte00bilsrich.epub and add epub.sh to rebuild it.
Exclude some junk files when zipping EPUB
Serialize as XHTML, unfortunately required by EPUB 2.0

Also jump through some polyglot hoops just to be safe.
Ignore *.txt (input for worddiff.py, etc)
Remove a lot of EPUB cruft