SaVi satellite constellation visualizer savi-dev

Noting per-satellite markers to distinguish/group satellites in geomview.

Removing surrey url

Removing older surrey SaVi urls - http://savi.sf.net is the best place.

Fixing typo.

Adding starlink simulation to list of files in Makefile.

Adding a simulation of SpaceX Starlink's inner shell (November 2018 filing, 550km altitude)

Removing superfluous syntactic sugar around winfo test commands.

don't need that eval.

Tweaking plot saving to save coverage map if
coverage window is open.

Tweaks to satplot output.
Time now works.
outputting .ppm, which works more consistently in Xfig.