* fix#8: better regex to remove html entities
* add opf and ncx debug
* make epub content retrieval more flexible
* fix epub content retrieval: also support html files with <div>
- Use antchfx/xmlquery for easier XML parsing. No more regexp wrangling and the result is much more reliable over a variety of ebooks. Much good.
- fix chapter selection, look for `<?xml[...]` which is much more reliable
- add option `-x` to dump the XML ebook source for debugging
- add color and color config support
- fix epub parsing
- add variable margin (left and right arrow keys)
- add help screen (hit `?`)
- add config file support