Merge branch 'master' into staging-next

There ver very many conflicts, basically all due to
name -> pname+version.  Fortunately, almost everything was auto-resolved
by kdiff3, and for now I just fixed up a couple evaluation problems,
as verified by the tarball job.  There might be some fallback to these
conflicts, but I believe it should be minimal.

Hydra nixpkgs: ?compare=1538299

pkgs/development/libraries/librealsense/default.nix

@@ -2,13 +2,13 @@
 
 stdenv.mkDerivation rec {
   pname = "librealsense";
-  version = "2.23.0";
+  version = "2.25.0";
 
   src = fetchFromGitHub {
     owner = "IntelRealSense";
     repo = "librealsense";
     rev = "v${version}";
-    sha256 = "055fvfmkfi71bk7yxa527awq5qrq4dni5xhlaldhak2vlis8glwk";
+    sha256 = "029qps0bbck0m2xj0mb5g3pgkk7a1zq8wcilfkvpx72sn7039xvw";
   };
 
   buildInputs = [