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/development/python-modules/dbus/default.nix

@@ -1,4 +1,4 @@
-{ lib, fetchurl, buildPythonPackage, python, pkgconfig, dbus, dbus-glib, dbus_tools, isPyPy
+{ lib, fetchurl, buildPythonPackage, python, pkgconfig, dbus, dbus-glib, isPyPy
 , ncurses, pygobject3 }:
 
 if isPyPy then throw "dbus-python not supported for interpreter ${python.executable}" else buildPythonPackage rec {
@@ -15,7 +15,7 @@ if isPyPy then throw "dbus-python not supported for interpreter ${python.executa
 
   nativeBuildInputs = [ pkgconfig ];
   buildInputs = [ dbus dbus-glib ]
-    ++ lib.optionals doCheck [ dbus_tools pygobject3 ]
+    ++ lib.optionals doCheck [ pygobject3 ]
     # My guess why it's sometimes trying to -lncurses.
     # It seems not to retain the dependency anyway.
     ++ lib.optional (! python ? modules) ncurses;