OOHASHI Daichi

I tried this branch and got an error like below: ```console $ nix run ".#satysfi" -- ./tests/images/test.saty ... ---- ---- ---- ---- embedding fonts ... ! [Error] cannot load image...

The assertion causing this error was introduced at the same time as `PBHookPageBreak` was introduced (https://github.com/gfngfn/SATySFi/commit/c6699b3a7369cf9b862d7f1b3cbe566d09292565). It might suffice to fix the problem to handle `PBHookPageBreak` properly in `Main__PageBreak.chop_single_column.normalize_after_break.omit_redundant_clear`

Some my thoughts: * I think it would be generally nice to reduce dependencies on Unix-specific commands. Should we remove dependencies on `make` and `sh` (to download fonts and install...

Ah, I noticed this message. It is emitted only for interlaced images (in this case, basi0g01.png). If we use only non-interlaced pngs, we do not see this message. I think...

Ah, sorry for confusing you with my non-portable commit message. I executed `ocp-indent -i src/**/*.ml{,i}` on zsh with `extended_glob` enabled. Zsh's `**` is [recursive glob](http://zsh.sourceforge.net/Doc/Release/Expansion.html#Recursive-Globbing) as in `.gitignore`. This PR...

rebased to the current master.

It seems hard to keep the patch mergeable, so I dropped the applying existing files part from the PR.

related: #217

After some searching, I found that upcoming camlpdf 2.5 introduces `CAMLPDF_REPRODUCIBLE_IDS` environment variable [^1] which ensures reproducible ids. I think it would be modester to use a method like this...

Current code calls the id generating function `Pdf.generate_id` via (SATySFi) `HandlePdf.write_to_file` → (CamlPDF) `Pdfwrite.pdf_to_file` → `Pdfwrite.pdf_to_file_options` → `Pdfwrite.change_id` → `Pdf.generate_id`. `Pdfwrite.pdf_to_file_options` function does not call `Pdfwrite.change_id` if `mkid` argument is...