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/tools/flatpak-builder/default.nix

@@ -25,7 +25,7 @@
 , gitMinimal
 , glib
 , gnutar
-, json_glib
+, json-glib
 , libcap
 , libdwarf
 , libsoup
@@ -67,7 +67,7 @@ in stdenv.mkDerivation rec {
     elfutils
     flatpak
     glib
-    json_glib
+    json-glib
     libcap
     libdwarf
     libsoup