Remove AlternateTransportsMode.

This conflicts with undeploy orders and has been largely
superseded by queued enter orders.

OpenRA.Mods.Common/Activities/EnterTransport.cs

@@ -80,57 +80,4 @@ namespace OpenRA.Mods.Common.Activities
 			base.Cancel(self, keepQueue);
 		}
 	}
-
-	class EnterTransports : Activity
-	{
-		readonly string type;
-		readonly Passenger passenger;
-
-		public EnterTransports(Actor self, Target primaryTarget)
-		{
-			passenger = self.Trait<Passenger>();
-			if (primaryTarget.Type == TargetType.Actor)
-				type = primaryTarget.Actor.Info.Name;
-
-			QueueChild(self, new EnterTransport(self, primaryTarget));
-		}
-
-		public override Activity Tick(Actor self)
-		{
-			if (ChildActivity != null)
-			{
-				ChildActivity = ActivityUtils.RunActivity(self, ChildActivity);
-				if (ChildActivity != null)
-					return this;
-			}
-
-			// Try and find a new transport nearby
-			if (IsCanceling || string.IsNullOrEmpty(type))
-				return NextActivity;
-
-			Func<Actor, bool> isValidTransport = a =>
-			{
-				var c = a.TraitOrDefault<Cargo>();
-				return c != null && c.Info.Types.Contains(passenger.Info.CargoType) &&
-				       (c.Unloading || c.CanLoad(a, self));
-			};
-
-			var candidates = self.World.FindActorsInCircle(self.CenterPosition, passenger.Info.AlternateTransportScanRange)
-				.Where(isValidTransport)
-				.ToList();
-
-			// Prefer transports of the same type as the primary
-			var transport = candidates.Where(a => a.Info.Name == type).ClosestTo(self);
-			if (transport == null)
-				transport = candidates.ClosestTo(self);
-
-			if (transport != null)
-			{
-				QueueChild(self, ActivityUtils.RunActivity(self, new EnterTransport(self, Target.FromActor(transport))), true);
-				return this;
-			}
-
-			return NextActivity;
-		}
-	}
 }