nsd: add package version 4.0.3

(cherry picked from commit e59c465103db779bba9259c5aa228773ed99d42a)
pkgs/nsd: Allow to easily override the package.

Allowing to use nixpkgs config to provide different defaults is not
going to help us here, so we would like to use nsd.override {} in order
to supply the correct options in the module.

Eventually removing the nixpkgs config option would make sense here as
well.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>
(cherry picked from commit fd9c8fa3dcabf4a9def05779c6b2d837e0d8d183)

Conflicts:
	pkgs/top-level/all-packages.nix
nsd: add hrdinka to maintainers

(cherry picked from commit 29b425862225715b9b8ea6a9a43807affa4ee669)
nsd: update to version 4.1.0

(cherry picked from commit f1b3196f2d69c7bfb922c64adb65515d43bb67d0)
nsd: fix description, license and platforms

(cherry picked from commit f5cd9d2460a06c86a7be1af626de7d982f50882e)