Temporarily work around a bug in maybe libzip
Temporarily work around a bug in maybe libzip

This references #1. Calling zip_fopen() causes a segfault in
libzip, despite all arguments seemingly being valid. It seems
that calling zip_name_locate either in zip_fopen() or from
_epub_read_file_in_zip() causes the problem. I'm not precisely
sure what the pathology is, but it definitely appears to be
somewhere in libzip. It requires further debugging, but we can
work around it for now.

apeiron/books,apeiron/books