* fix#3: added h ui command to toggle ui
* fix#4: added -N flag to disable colors
* fixed styling of line numbers (-n)
* fix#5 add usage section
* add pkg/epub module readme
* add license terms to all file headers
* fixed usage printing
* added basic unit tests
* run the tests only on linux due to the use of base64 utitlity
- 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
