Import sanitize.py from chariotsforapollo.git
Split the parts into separate files (again)

This time, do it at the source, not in the generated files.
Help sanitize.py by changing some quotation marks in the source

The Rudolph quote does has the question mark outside the quotation mark
in the book, but that's the only such case, in 8 other cases it is the
other way around, many more if other punctuation is considered.
Fix and hack sanitize.py to match the output of sanitize.js

This is just to verify, some hacks will be reverted.
Replace sanitize.js + epub.sh with sanitize.py + Makefile

The generated EPUBs have been verified identical except for the
intentional change in ch10.htm and commit SHA1 in about.htm.