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/applications/window-managers/afterstep/default.nix

@@ -2,7 +2,7 @@
 , libjpeg, libtiff, libpng, freetype
 , fltk, gtk
 , libX11, libXext, libICE
-, dbus, dbus_libs
+, dbus
 }:
 
 stdenv.mkDerivation rec {
@@ -17,7 +17,7 @@ stdenv.mkDerivation rec {
   };
 
   nativeBuildInputs = [ pkgconfig ];
-  buildInputs = [ libjpeg libtiff libpng freetype fltk gtk libX11 libXext libICE dbus dbus_libs ];
+  buildInputs = [ libjpeg libtiff libpng freetype fltk gtk libX11 libXext libICE dbus ];
 
   # A strange type of bug: dbus is not immediately found by pkgconfig
   preConfigure = ''