SaVi satellite constellation visualizer savi-dev

Adding first attempts at Singh's efficient four-satellite systems
as described in Nature Communications.

Minor Draim tweaks.

If we launch SaVi and immediately Empty space, freeze. Fixing that, inelegantly.
Problem with the Details window content.

Minor tweaks to Draim comments.

Minor tweaks to Karousel script for clarity.

Fixing comment hashes.

using dx.doi.org for consistency.

Minor tweaks to help intro text to give scripts location.

Notes on the Draim design - there's a Nature paper referencing it.

Removing unneeded global cones_flag