Major Haskell packages overhaul.

Several changes, some highlights:

  * Structure of haskell-packages.nix updated. It's now easier to
    select different default versions of packages for different
    versions of GHC.

  * GHC 7.0.2 is now default.

  * Haskell Platform 2011.2.0.0 has been added and is now default.

  * Several packages have been updated
    (gtk2hs, gitit, xmonad, darcs, ...).

  * Some old packages have been removed.

svn path=/nixpkgs/trunk/; revision=26288

pkgs/development/libraries/haskell/HTTP/4000.1.1.nix

@@ -0,0 +1,12 @@
+{cabal, mtl, network, parsec}:
+
+cabal.mkDerivation (self : {
+  pname = "HTTP";
+  version = "4000.1.1"; # Haskell Platform 2011.2.0.0
+  sha256 = "09khx5fb673a0d7m3bl39xjdxvc60m52rmm4865cha2mby0zidy3";
+  propagatedBuildInputs = [mtl network parsec];
+  meta = {
+    description = "a Haskell library for client-side HTTP";
+  };
+})
+