Requested feature enhancements for viewing footprints and ground tracks

I recently discovered Gpredict and have found it to be a very useful program to supplement traditional teaching materials in satellite geodesy courses. Many thanks to Alexandru Csete for making the program and code available! I would like to make a few suggestions for minor revisions:

  1. Allow the footprint demarcation line to be turned off (not just the footprint highlighting).

  2. Cause the program to remember the settings of both the footprint and ground track visibility settings. I am constantly having to go back to the right-click menu to turn ground track back on.

  3. Add a setting for the line thickness of ground tracks and footprints, even if just thin and bold options. The current line thickness can seem a bit too thin sometimes.