SaVi satellite constellation visualizer savi-dev

Fixing url downloads from celetrak to work with their new fancy script,
which can be set to the legacy tle format.

Adding coverage menu options to lighten or darken diversity and decay on the map.

This really needs to be an easy to use slider controlling both.

Adding check in for Mac OS X when unix tcl is in use,
to draw windowpanes in white.
THought I added this in previously...

Tidying up graticule code so horizontal lines don't vibrate.

Putting earth map options (graticule, tropics, equator) up with map option
to save space.

Minor notes on the -redrawn-menus flag, which is turning
out to be more trouble than it's worth.

Notes on how to build SaVi with recent Mac OS X -
the supplied Tk is deprecated and doesn't work,
so you need to install a later matching version
of both Tcl and Tk.

Noting that we're tested with Tcl/TK 9.0.

First cut at tcl/tk 9.0 support.

It turned out that the processor #if version testing
was falling through to the oldest Tk_PhotoPutBlock,
so just had to tweak the tests cases to support
version 9.0 properly. (yes, 8.4 is Special.)

Don't hit geomview commands if not running geomview.