Overlapping colonization screens during autopilot phase.

If you have enough colony ships with stars as targets arrive during the same turn the colonization screens start overlapping, making it impossible to enter initial projects for some of them. These need to be serialized so that the "done" button for one has to be pressed before the next one is presented.

There have been many cases reported where proper serialization of screens is not done, some of them fixed, some not.