* 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
Many (less easily automatically converted) old-style strings
remain.
Where there was any possible ambiguity about the exact version or
variant intended, nothing was changed. IANAL, nor a search robot.
Use `with stdenv.lib` wherever it makes sense.