Comment 7 for bug 1079766

Perfect !

Still some progress for the next version :
- allow to plot the date and time on the sky position (every n "yellow circles").
- ability to choose the size and shape of the "yellow circles", such as "+", "x", "o" or "nothing" and allow to connect (or not) the dots with a line.
- show a legend on the screen with the name of the object, the start/end dates, the time step