notmuch with inheritable-tags-hack for thread muting

the muted tag is supposed to be inherited by messages of the same
thread, effictely muting a thread. A muted thread will not show up in
your inbox anymore. Current implementation is hackish but functional.

big thank you to amdragon!

svn path=/nixpkgs/trunk/; revision=26878

pkgs/development/libraries/xapian/1_2.nix

@@ -0,0 +1,18 @@
+{ stdenv, fetchurl, zlib }:
+
+stdenv.mkDerivation {
+  name = "xapian-1.2.4";
+
+  src = fetchurl {
+    url = http://oligarchy.co.uk/xapian/1.2.4/xapian-core-1.2.4.tar.gz;
+    sha256 = "0665c02aa1a6cccc071d4f2b426ac0feb6f4f8f0e50da720ce375ae6d3d6f348";
+  };
+
+  buildInputs = [zlib];
+
+  meta = { 
+    description = "Xapian Probabilistic Information Retrieval library";
+    homepage = "http://xapian.org";
+    license = "GPLv2";
+  };
+}