window: destroy window surfaces and title

Plugs leaks from struct window in window_destroy().

Signed-off-by: Pekka Paalanen <ppaalanen@gmail.com>
diff --git a/clients/window.c b/clients/window.c
index f0a90a7..3f6dafc 100644
--- a/clients/window.c
+++ b/clients/window.c
@@ -997,6 +997,13 @@
 		wl_shell_surface_destroy(window->shell_surface);
 	wl_surface_destroy(window->surface);
 	wl_list_remove(&window->link);
+
+	if (window->cairo_surface != NULL)
+		cairo_surface_destroy(window->cairo_surface);
+	if (window->pending_surface != NULL)
+		cairo_surface_destroy(window->pending_surface);
+
+	free(window->title);
 	free(window);
 }