tzdata: Provide lib as an additional output.

We're already using tzcode inside tzdata, so let's make it available as
an output here. The reason we need it is in order to compile OpenCFLite.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>

pkgs/data/misc/tzdata/default.nix

@@ -17,13 +17,17 @@ stdenv.mkDerivation rec {
     ];
 
   sourceRoot = ".";
+  outputs = [ "out" "lib" ];
 
-  makeFlags = "TOPDIR=$(out) TZDIR=$(out)/share/zoneinfo ETCDIR=$(TMPDIR)/etc LIBDIR=$(TMPDIR)/lib MANDIR=$(TMPDIR)/man AWK=awk";
+  makeFlags = "TOPDIR=$(out) TZDIR=$(out)/share/zoneinfo ETCDIR=$(TMPDIR)/etc LIBDIR=$(lib)/lib MANDIR=$(TMPDIR)/man AWK=awk";
 
   postInstall =
     ''
       mv $out/share/zoneinfo-posix $out/share/zoneinfo/posix
       mv $out/share/zoneinfo-leaps $out/share/zoneinfo/right
+
+      ensureDir "$lib/include"
+      cp tzfile.h "$lib/include/tzfile.h"
     '';
 
   meta = {