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/mar1d/default.nix

@@ -2,7 +2,7 @@
 , fetchFromGitHub
 , cmake
 , libGLU
-, x11
+, xlibsWrapper
 , xorg
 , xinput_calibrator
 , doxygen
@@ -42,7 +42,7 @@ stdenv.mkDerivation rec {
       libao
       libpthreadstubs
       libGLU
-      x11
+      xlibsWrapper
       xinput_calibrator
       xorg.libXrandr
       xorg.libXi