sharutils: making them crossbuild, thanks to a patch.

Patch taken from:
http://repository.timesys.com/buildsources/s/sharutils/sharutils-4.11.1/sharutils-4.11.1-cross-binary-mode-popen.patch
after a google search for the guilty part of 'configure'.

pkgs/tools/archivers/sharutils/default.nix

@@ -13,6 +13,10 @@ stdenv.mkDerivation rec {
 
   doCheck = true;
 
+  crossAttrs = {
+    patches = [ ./sharutils-4.11.1-cross-binary-mode-popen.patch ];
+  };
+
   meta = {
     description = "GNU Sharutils, tools for remote synchronization and `shell archives'";