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/display-managers/lightdm/default.nix

@@ -1,5 +1,5 @@
 { stdenv, fetchurl, pam, pkgconfig, libxcb, glib, libXdmcp, itstool, libxml2
-, intltool, xlibsWrapper, libxklavier, libgcrypt, libaudit, coreutils
+, intltool, xlibsWrapper, libxklavier, libgcrypt, audit, coreutils
 , qt4 ? null
 , withQt5 ? false, qtbase
 }:
@@ -21,7 +21,7 @@ stdenv.mkDerivation rec {
   nativeBuildInputs = [ pkgconfig intltool ];
   buildInputs = [
     pam libxcb glib libXdmcp itstool libxml2 libxklavier libgcrypt
-    qt4 libaudit
+    qt4 audit
   ] ++ optional withQt5 qtbase;
 
   configureFlags = [