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/tools/misc/fileschanged/default.nix

@@ -1,4 +1,4 @@
-{ stdenv, fetchurl, fam }:
+{ stdenv, fetchurl, gamin }:
 
 stdenv.mkDerivation rec {
   name = "fileschanged-0.6.9";
@@ -8,7 +8,7 @@ stdenv.mkDerivation rec {
     sha256 = "0ajc9h023vzpnlqqjli4wbvs0q36nr5p9msc3wzbic8rk687qcxc";
   };
 
-  buildInputs = [ fam ];
+  buildInputs = [ gamin ];
 
   patches = [./unused-variables.debian.patch];