Replace DomainIndex passability hack with Locomotor boolean

OpenRA.Mods.Common/Traits/World/DomainIndex.cs

@@ -44,8 +44,7 @@ namespace OpenRA.Mods.Common.Traits
 			if (p1.Layer != 0 || p2.Layer != 0)
 				return true;
 
-			// HACK: Workaround until we can generalize movement classes
-			if (li is SubterraneanLocomotorInfo || li is JumpjetLocomotorInfo)
+			if (li.DisableDomainPassabilityCheck)
 				return true;
 
 			var movementClass = li.GetMovementClass(tileSet);

OpenRA.Mods.Common/Traits/World/JumpjetLocomotor.cs

@@ -25,6 +25,8 @@ namespace OpenRA.Mods.Common.Traits
 		[Desc("Can this actor transition on slopes?")]
 		public readonly bool JumpjetTransitionOnRamps = true;
 
+		public override bool DisableDomainPassabilityCheck { get { return true; } }
+
 		public override object Create(ActorInitializer init) { return new JumpjetLocomotor(init.Self, this); }
 	}
 

OpenRA.Mods.Common/Traits/World/Locomotor.cs

@@ -287,6 +287,8 @@ namespace OpenRA.Mods.Common.Traits
 			return true;
 		}
 
+		public virtual bool DisableDomainPassabilityCheck { get { return false; } }
+
 		public virtual object Create(ActorInitializer init) { return new Locomotor(init.Self, this); }
 	}
 

OpenRA.Mods.Common/Traits/World/SubterraneanLocomotor.cs

@@ -29,6 +29,8 @@ namespace OpenRA.Mods.Common.Traits
 		[Desc("Depth at which the subterranian condition is applied.")]
 		public readonly WDist SubterraneanTransitionDepth = new WDist(-1024);
 
+		public override bool DisableDomainPassabilityCheck { get { return true; } }
+
 		public override object Create(ActorInitializer init) { return new SubterraneanLocomotor(init.Self, this); }
 	}