Re-add minwin gtk example

samples/minwin_gtk/minwin/unittest.d

@@ -0,0 +1,17 @@
+/* MinWin unittest
+ *
+ * Written by Ben Hinkle and released to the public domain, as
+ * explained at http://creativecommons.org/licenses/publicdomain
+ * Report comments and bugs at dsource: http://www.dsource.org/projects/minwin
+ */
+
+import minwin.all;
+
+extern (C)
+int MinWinMain(Application* app) {
+    Point p = XY(100,100);
+    Group g = new Group(null);
+    app.rsrc("100");
+    return 0;
+}
+