private static String integerIfPossible(final double value) {
        if (value == (long) value) {
            return String.format(Locale.ENGLISH, "%d", (long) value);
        }
        return String.format(Locale.ENGLISH, "%s", value);
    }
Writes one waypoint entry for cache waypoint.
main/src/main/java/cgeo/geocaching/export/GpxSerializer.java