Merge #2030: add openra game (C&C RTS engine)

Modifications from @vcunat, who tried Dune,
but it typically segfaults in mono after a few minutes
(IMHO unlikely to be a problem with packaging it).

pkgs/games/openra/default.nix

@@ -0,0 +1,44 @@
+{ stdenv, fetchurl, mono, makeWrapper
+, SDL2, freetype, openal
+}:
+
+let
+  version = "20131223";
+in stdenv.mkDerivation rec {
+  name = "openra-${version}";
+
+  meta = with stdenv.lib; {
+    description = "Real Time Strategy game engine recreates the C&C titles";
+    homepage    = "http://www.open-ra.org/";
+    license     = licenses.gpl3;
+    platforms   = platforms.linux;
+    maintainers = with maintainers; [ iyzsong ];
+  };
+
+  src = fetchurl {
+    name = "${name}.tar.gz";
+    url = "https://github.com/OpenRA/OpenRA/archive/release-${version}.tar.gz";
+    sha256 = "1gfz6iiccajp86qc7xw5w843bng69k9zplvmipxxbspvr7byhw0c";
+  };
+
+  dontStrip = true;
+
+  nativeBuildInputs = [ mono makeWrapper ];
+
+  patchPhase = ''
+    sed -i 's/^VERSION.*/VERSION = release-${version}/g' Makefile
+  '';
+
+  preConfigure = ''
+    makeFlags="prefix=$out"
+    make version
+  '';
+
+  postInstall = with stdenv.lib; let
+    runtime = makeLibraryPath [ SDL2 freetype openal ];
+  in ''
+    wrapProgram $out/bin/openra \
+      --prefix PATH : "${mono}/bin" \
+      --prefix LD_LIBRARY_PATH : "${runtime}"
+  '';
+}

pkgs/top-level/all-packages.nix

@@ -9993,6 +9993,8 @@ let
 
   oilrush = callPackage ../games/oilrush { };
 
+  openra = callPackage ../games/openra { };
+
   openttd = callPackage ../games/openttd {
     zlib = zlibStatic;
   };