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/X11/xwinwrap/default.nix

@@ -1,4 +1,4 @@
-{ stdenv, fetchbzr, x11 }:
+{ stdenv, fetchbzr, xlibsWrapper }:
 
 let
   version = "4";
@@ -13,7 +13,7 @@ stdenv.mkDerivation {
   };
 
   buildInputs = [
-    x11
+    xlibsWrapper
   ];
 
   buildPhase = if stdenv.system == "x86_64-linux" then ''