Add direction arrows to ground tracks

[danapple]

When displaying the ground tracks in the multi-satellite view, it would be helpful to having arrows on at least the first ground track indicating the direction of travel of each satellite.

I suggest settings for "number of arrows" (scalar) and "distance between arrows" (degrees/radians) to allow for customization. Arrows can be only on future tracks and do not have to be on the past track.

[vk6bbt]

I would add my thoughts that future ground tracks are the same as the current line and past ground track is a dotted line, this may be more visually appealing?