xlibs: replace occurrences by xorg

This seems to have been confusing people, using both xlibs and xorg, etc.
- Avoided renaming local (and different) xlibs binding in gcc*.
- Fixed cases where both xorg and xlibs were used.
Hopefully everything still works as before.

pkgs/tools/misc/pipelight/default.nix

@@ -1,4 +1,4 @@
-{ stdenv, fetchurl, fetchgit, autoconf, automake, wineStaging, perl, xlibs
+{ stdenv, fetchurl, fetchgit, autoconf, automake, wineStaging, perl, xorg
   , gnupg, gcc_multi, mesa, curl, bash, cacert, cabextract, utillinux, attr
   }:
 
@@ -19,7 +19,7 @@ in stdenv.mkDerivation rec {
     sha256 = "1i440rf22fmd2w86dlm1mpi3nb7410rfczc0yldnhgsvp5p3sm5f";
   };
 
-  buildInputs = [ wine_custom xlibs.libX11 gcc_multi mesa curl ];
+  buildInputs = [ wine_custom xorg.libX11 gcc_multi mesa curl ];
   propagatedbuildInputs = [ curl cabextract ];
 
   patches = [ ./pipelight.patch ];