treewide: remove aliases in nixpkgs

This makes the command ‘nix-env -qa -f. --arg config '{skipAliases =
true;}'’ work in Nixpkgs.

Misc...

- qtikz: use libsForQt5.callPackage

  This ensures we get the right poppler.

- rewrites:

  docbook5_xsl -> docbook_xsl_ns
  docbook_xml_xslt -> docbook_xsl

diffpdf: fixup

pkgs/games/openrw/default.nix

@@ -1,4 +1,4 @@
-{ stdenv, fetchgit, cmake, sfml, libGLU_combined, bullet, glm, libmad, x11, openal
+{ stdenv, fetchgit, cmake, sfml, libGLU_combined, bullet, glm, libmad, xlibsWrapper, openal
 , SDL2, boost, ffmpeg }:
 
 stdenv.mkDerivation rec {
@@ -13,7 +13,7 @@ stdenv.mkDerivation rec {
   };
 
   buildInputs = [
-    cmake sfml libGLU_combined bullet glm libmad x11 openal SDL2 boost ffmpeg
+    cmake sfml libGLU_combined bullet glm libmad xlibsWrapper openal SDL2 boost ffmpeg
   ];
 
   meta = with stdenv.lib; {