@Override
    public boolean onCreateOptionsMenu(final Menu menu) {
        getMenuInflater().inflate(R.menu.menu_ok_cancel, menu);
        menu.findItem(R.id.menu_optimize).setVisible(true);
        menu.findItem(R.id.menu_invert_order).setVisible(true);
        return true;
    }
experimental function for optimizing a route by using tsp-specific algorithm
main/src/main/java/cgeo/geocaching/maps/routing/RouteSortActivity.java