* 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
The raleway fonts need to be copied from their /share folder to be
included properly.
They are also `.otf`-fonts, so they should live in `opentype` folders.
