@Override
    public void setMapRotation(final int mapRotation) {
        super.setMapRotation(mapRotation);
        mMap.getEventLayer().enableRotation(mapRotation == Settings.MAPROTATION_MANUAL);
    }
call this instead of VTM.layers().add so that we can keep track of layers added by the tile provider
main/src/main/java/cgeo/geocaching/unifiedmap/mapsforgevtm/MapsforgeVtmFragment.java