* make font derivations fixed-output where applicable
* fix dead links
* `stdenv.lib` -> `lib` where `stdenv` is not involved
* remove `meta.platforms = [ unix ]` and `meta.platforms = [ linux ]` because the restriction has no sense for data packages
Kept the old hacks where they don't break the build in case they things
they fix are still relevant.
I checked that the upgrade doesn't break:
1) Asymptote and EProver builds.
2) My XeLaTeX demo from configurations/ repository.
3) Some of my own files.
The upgrade fixes problems with simultaneous use of 3D and LaTeX labels
in Asymptote.
Please provide a test that worked previously and is broken now if you
need to revert this update or its parts.
