Three Games and Perl Support for Irssi

Here are four patches. Three of them add expressions for games. The
fourth, irssi-perl.patch, adds perl as an input for irssi, so that one
can run perl plugins in irssi. I didn't make the perl input optional,
but maybe it should be to keep the irssi expression light.

svn path=/nixpkgs/trunk/; revision=21813

pkgs/games/gnugo/default.nix

@@ -0,0 +1,24 @@
+{ stdenv, fetchurl }:
+
+let
+
+    versionNumber = "3.8";
+
+in
+
+stdenv.mkDerivation {
+
+  name = "gnugo-${versionNumber}";
+
+  src = fetchurl {
+    url = "mirror://gnu/gnugo/gnugo-${versionNumber}.tar.gz";
+    sha256 = "0wkahvqpzq6lzl5r49a4sd4p52frdmphnqsfdv7gdp24bykdfs6s";
+  };
+
+  meta = {
+    description = "GNU Go - A computer go player";
+    homepage = "http://http://www.gnu.org/software/gnugo/";
+    license = "GPLv3";
+  };
+
+}