Starports sometimes push each other around

[IsaacLic]

When there are several systems, Starports sometimes end up too close to each other. When that happens, they'll both get moved away from each other, which often can cause them to swing wildly, possibly sending the player flying. Presumably, they shouldn't do that.

When the Starport is still a FarObject, it moves to be as close as possible to the other planet or system, the same way that it does as a SolObject. However, once it becomes a SolObject (because the player moved close enough), it starts checking to see if another starport is nearby. Since they can now overlap, the starports move to ensure that they aren't touching. In the current code, they immediately move far enough away that they aren't touching the other starport. Since each starport is suddenly moving, it can crash into the player, sending the ship flying. If it overlaps with a Starport on the other side, it can also bounce back and forth between the two.

How to reproduce

• Start a new game with several systems. The more there are, the easier this is to reproduce.
• Take starports to a system near the edge, so that several starports link to systems that are approximately lined up. (This will cause the starports to become close to each other.)
• When the player gets close, if the starports are close enough, they should shake wildly. If not, fly away and try again.