Revert "Merge branch 'staging'" due to glibc

The main output started to retain dependency on bootstrap-tools; see
https://github.com/NixOS/nixpkgs/pull/15867#issuecomment-227949096

This reverts commit c05d829598, reversing
changes made to f073df60d6.

pkgs/data/sgml+xml/stylesheets/xslt/docbook-xsl/default.nix

@@ -3,7 +3,7 @@
 let
 
   common = { pname, sha256 }: stdenv.mkDerivation rec {
-    name = "${pname}-1.79.1";
+    name = "${pname}-1.78.1";
 
     src = fetchurl {
       url = "mirror://sourceforge/docbook/${name}.tar.bz2";
@@ -35,12 +35,12 @@ in {
 
   docbook_xsl = common {
     pname = "docbook-xsl";
-    sha256 = "0s59lihif2fr7rznckxr2kfyrvkirv76r1zvidp9b5mj28p4apvj";
+    sha256 = "0rxl013ncmz1n6ymk2idvx3hix9pdabk8xn01cpcv32wmfb753y9";
   };
 
   docbook_xsl_ns = common {
     pname = "docbook-xsl-ns";
-    sha256 = "170ggf5dgjar65kkn5n33kvjr3pdinpj66nnxfx8b2avw0k91jin";
+    sha256 = "1x3sc0axk9z3i6n0jhlsmzlmb723a4sjgslm9g12by6phirdx3ng";
   };
 
 }