Add Kodi retroarch launchers

pkgs/misc/emulators/retroarch/kodi-advanced-launchers.nix

···
+{ stdenv, pkgs, cores }:
+
+assert cores != [];
+
+with pkgs.lib;
+
+let
+
+  script = exec: ''
+    #!${stdenv.shell}
+    nohup sh -c "sleep 1 && pkill -SIGSTOP kodi" &
+    nohup sh -c "${exec} '$@' -f;pkill -SIGCONT kodi"
+  '';
+  scriptSh = exec: pkgs.writeScript ("kodi-"+exec.name) (script exec.path);
+  execs = map (core: rec { name = core.core; path = core+"/bin/retroarch-"+name;}) cores;
+
+in
+
+stdenv.mkDerivation rec {
+  name = "kodi-retroarch-advanced-launchers-${version}";
+  version = "0.2";
+
+  dontBuild = true;
+
+  buildCommand = ''
+    mkdir -p $out/bin
+    ${stdenv.lib.concatMapStrings (exec: "ln -s ${scriptSh exec} $out/bin/kodi-${exec.name};") execs}
+  '';
+
+  meta = {
+    description = "Kodi retroarch advanced launchers";
+    longDescription = ''
+      These retroarch launchers are intended to be used with
+      anglescry advanced launcher for Kodi since device input is
+      caught by both Kodi and the retroarch process.
+    '';
+    license = stdenv.lib.licenses.gpl3;
+  };
+}

pkgs/top-level/all-packages.nix

···
       cores = retroArchCores;
   };
 
+  kodi-retroarch-advanced-launchers =
+    callPackage ../misc/emulators/retroarch/kodi-advanced-launchers.nix {
+      cores = retroArchCores;
+  };
+
   xca = callPackage ../applications/misc/xca { };
 
   xcalib = callPackage ../tools/X11/xcalib { };