SaVi satellite constellation visualizer savi-dev

Fixing all-white color display - PREV was set to zero after building, so we bring it inline.

Removing unused NUM_COLORS_NEXT variable.

New shading submenu is now working as it should.

Another stab at changing colors without destroying and recreating
entire window - this version finally does that properly.

Coverage shade/levels popup now redraws just the frame-in-frame,
without having to destroy and recreate the coverage window.

Minor tweaks to coverage window geometry for vertically
stretched windows.

Adding an in-verage-window shades control.
This respawns the coverage window, because we haven't
figurd out how to redraw window subelements yet.

More tweaks to Constellations popup menu grouping.

Note on source of parameters - the FCC filing.

Improving packaging notes.