Add EPUB output option.

[rcoacci]

Simple epub ebook format generation using tex4ebook, alongside PDF.
The config file is necessary for correct image sizing.
Fixes #13

[sobkas]

It doesn't work:

[STATUS]  tex4ebook: Conversion started
[STATUS]  tex4ebook: Input file: book.tex
[WARNING] tocid: char-def module not found
[WARNING] tocid: cannot fix section id's
sh: 1: rungs: not found
sh: 1: rungs: not found
sh: 1: rungs: not found
sh: 1: rungs: not found
sh: 1: rungs: not found
sh: 1: rungs: not found
sh: 1: rungs: not found
sh: 1: rungs: not found
sh: 1: rungs: not found
sh: 1: rungs: not found
sh: 1: rungs: not found
sh: 1: rungs: not found
sh: 1: rungs: not found
[ERROR]   mkutils: File fig/os-.png doesn't exist
cp: cannot stat 'fig/os-.png': No such file or directory
[ERROR]   mkutils: File fig/mkernel-.png doesn't exist
cp: cannot stat 'fig/mkernel-.png': No such file or directory
[ERROR]   mkutils: File fig/as-.png doesn't exist
cp: cannot stat 'fig/as-.png': No such file or directory
[ERROR]   mkutils: File fig/riscv_address-.png doesn't exist
cp: cannot stat 'fig/riscv_address-.png': No such file or directory
[ERROR]   mkutils: File fig/riscv_pagetable-.png doesn't exist
cp: cannot stat 'fig/riscv_pagetable-.png': No such file or directory
[ERROR]   mkutils: File fig/xv6_layout-.png doesn't exist
cp: cannot stat 'fig/xv6_layout-.png': No such file or directory
[ERROR]   mkutils: File fig/processlayout-.png doesn't exist
cp: cannot stat 'fig/processlayout-.png': No such file or directory
[ERROR]   mkutils: File fig/smp-.png doesn't exist
cp: cannot stat 'fig/smp-.png': No such file or directory
[ERROR]   mkutils: File fig/race-.png doesn't exist
cp: cannot stat 'fig/race-.png': No such file or directory
[ERROR]   mkutils: File fig/switch-.png doesn't exist
cp: cannot stat 'fig/switch-.png': No such file or directory
[ERROR]   mkutils: File fig/fslayer-.png doesn't exist
cp: cannot stat 'fig/fslayer-.png': No such file or directory
[ERROR]   mkutils: File fig/fslayout-.png doesn't exist
cp: cannot stat 'fig/fslayout-.png': No such file or directory
[ERROR]   mkutils: File fig/inode-.png doesn't exist
cp: cannot stat 'fig/inode-.png': No such file or directory
HTML Tidy for Linux version 5.8.0
[STATUS]  tex4ebook: Conversion finished
make: *** [Makefile:43: book.epub] Error 1

[rcoacci]

Oh, it seems that in the meantime the figures changed from png to svg/pdf, and probably changed their names too. I'll take a look and try to fix it.

[rcoacci]

Well actually, it worked for me when I tried the original branch, are you sure you have the ebb program @sobkas ? That's what generates the missing png files.

[rcoacci]

I've updated my branches, but for correct generation one needs either #32 or #35. Unfortunately it seems the maintainers are ignoring (or not aware of) the contributions from the community.