Overhaul target line rendering:

- Targets are now defined by the activities
- Queued activities are shown
- Support custom attack colors

OpenRA.Mods.Common/Activities/UnloadCargo.cs

@@ -122,7 +122,6 @@ namespace OpenRA.Mods.Common.Activities
 					actor.CancelActivity();
 					pos.SetVisualPosition(actor, spawn);
 					actor.QueueActivity(move.MoveIntoWorld(actor, exitSubCell.Value.First, exitSubCell.Value.Second));
-					actor.SetTargetLine(Target.FromCell(w, exitSubCell.Value.First, exitSubCell.Value.Second), Color.Green, false);
 					w.Add(actor);
 				});
 			}