xib2nib: move nsplist, plistcpp to own folder

These libraries could be used by other packages so list them in
all-packages.nix as well.

pkgs/development/libraries/NSPlist/default.nix

@@ -0,0 +1,14 @@
+{ stdenv, fetchFromGitHub, cmake }:
+
+stdenv.mkDerivation {
+  name = "NSPlist-713decf";
+
+  src = fetchFromGitHub {
+    owner = "matthewbauer";
+    repo = "NSPlist";
+    rev = "713decf06c1ef6c39a707bc99eb45ac9925f2b8a";
+    sha256 = "0v4yfiwfd08hmh2ydgy6pnmlzjbd96k78dsla9pfd56ka89aw74r";
+  };
+
+  buildInputs = [ cmake ];
+}

pkgs/development/libraries/PlistCpp/default.nix

@@ -0,0 +1,14 @@
+{ stdenv, fetchFromGitHub, cmake, boost, NSPlist, pugixml }:
+
+stdenv.mkDerivation {
+  name = "PlistCpp-11615d";
+
+  src = fetchFromGitHub {
+    owner = "matthewbauer";
+    repo = "PlistCpp";
+    rev = "11615deab3369356a182dabbf5bae30574967264";
+    sha256 = "10jn6bvm9vn6492zix2pd724v5h4lccmkqg3lxfw8r0qg3av0yzv";
+  };
+
+  buildInputs = [ cmake boost NSPlist pugixml ];
+}