This is a beta version to test new features:
- Switched to a custom epub generator, instead of the third-party library used so far, to be able to focus only on those features needed to create comic book files and add some new options.
- Added a new section to the Advanced options of the comic book conversion tool to allow creating epubs with the images embedded as base64 in the html (feature requested in issue #29) and limiting the image formats to only those allowed by the specification.