Code for creating epub files.
'epub.py' may be of general use.
The project as a whole is currently oriented towards converting
creating .epub files from Internet Archive book 'items', consisting of
metadata, 'abbyy' OCR output files, and page images.
Entry points -
* convert_iabook.py - main Internet Archive book converter
* condense_abbyy.py - create slightly-more-human-readable version of abbyy
* visualize_abbyy.py - create a directory of page images, marked with OCR
(Needs currently un-checked-in fonts)