continuation of #109595
pkgconfig was aliased in 2018, however, it remained in
all-packages.nix due to its wide usage. This cleans
up the remaining references to pkgs.pkgsconfig and
moves the entry to aliases.nix.
python3Packages.pkgconfig remained unchanged because
it's the canonical name of the upstream package
on pypi.
There are many more packages to fix, this is just a start.
Rules:
* Don't repeat the package name (not always that easy...)
* Start with capital letter
* Don't end with full stop
* Don't start with "The ..." or "A ..."
I've also added descriptions to some packages and rewritten others.
Some of these should be longDescriptions, but most others just
shouldn't contain newlines. E.g. write
description = "Bla";
and not
description = ''
Bla
'';
This pollutes "nix-env -qa --description" output.
svn path=/nixpkgs/trunk/; revision=14310
