Dark Guiding tweaks
Fixed a few issues with Dark Guiding.
- The Dark guiding interval could be set to 0.0s or very short values causing ridiculous computation.
- Synchronize the dark-guiding timing with the standard guiding by reseting the dark guiding timer when a guiding iteration starts.
- Dark guiding was emitting a 0ms DEC pulse on every iteration. It should not affect DEC.
- Removed/reworked some logging.