Added compile switch for restoring of last known date after power lost: In case timing date was lost the RTC has to be set to a proper time anyhow. Maybe this function does not add as much value as expected... => Added compile switch (deactivated) to allow easy reactivation if this function is wanted.

Heinrichs Weikamp OSTC4 update files.

The builds are for testing purposes only. Be careful, they might not work and are definitely not recommended for real dives.