firedrake: Moved to new overlay system and shared sub-scope

Firedrake contains a ton of inter-connected dependencies, many of
which are either firedrake specific or forked versions of upstream
packages.  Cleaner to create a firedrake sub-scope for all these.

pkgs/firedrake/hypre.nix

@@ -0,0 +1,30 @@
+{ stdenv, fetchFromGitHub, cmake
+, openmpi }:
+
+stdenv.mkDerivation rec {
+  version = "xsdk-0.2.0-rc2";
+  name = "hypre-${version}";
+
+  src = fetchFromGitHub {
+    owner = "LLNL";
+    repo = "hypre";
+    rev = "${version}";
+    sha256 = "0ql1zs0imv14q511aj5g82mfhlycy8rqa5b6rzzw86c4cslasgch";
+  };
+
+  buildInputs = [
+    cmake
+    openmpi
+  ];
+
+  sourceRoot = "source/src";
+  preConfigure = "cmakeFlags=\"-DHYPRE_INSTALL_PREFIX=$prefix $cmakeFlags\"";
+
+  makeFlags = [ "VERBOSE=1" ];
+
+  meta = with stdenv.lib; {
+    homepage = "http://www.llnl.gov/casc/hypre";
+    description = "Parallel solvers for sparse linear systems featuring multigrid methods.";
+    license = licenses.gpl2;
+  };
+}