Closes #93

This made sense some time ago. Nowdays, the whitewhale runner seems to
not really be reliable, so tagging jobs with it doesn't gain much.

Relates #45

Relates #45

Relates #45
Relates #93

Additionally, fix a typo.

Closes #96

- More tests
- More documentation
- Minor code cleanup

This should improve epub compatibility,
along with other formats as a side-effect

It's not mandatory to actually have a comment inside
comment delimiter, like `/**/`.

This should close #95.

without /etc/ld.so.cache available in the sandbox, tests fail on gentoo with:
/usr/bin/ffmpeg: error while loading shared libraries: libstdc++.so.6:
    cannot open shared object file: No such file or directory

This should make easier to get more metadata from
archive-based file formats.

This should closes  #90

This should solve collisions with people like me that
are copy/pasting the documentation, creating conflicts
with other extensions that are doing the very same thing.