Add a lint check for trait placement on hardcoded actor names.

OpenRA.Game/Traits/Player/FrozenActorLayer.cs

@@ -22,6 +22,7 @@ namespace OpenRA.Traits
 		void OnVisibilityChanged(FrozenActor frozen);
 	}
 
+	[TraitLocation(SystemActors.Player)]
 	[Desc("Required for FrozenUnderFog to work. Attach this to the player actor.")]
 	public class FrozenActorLayerInfo : TraitInfo, Requires<ShroudInfo>
 	{

OpenRA.Game/Traits/Player/PlayerColorPalette.cs

@@ -14,7 +14,8 @@ using OpenRA.Primitives;
 
 namespace OpenRA.Traits
 {
-	[Desc("Add this to the Player actor definition.")]
+	[TraitLocation(SystemActors.World | SystemActors.EditorWorld)]
+	[Desc("Add this to the World actor definition.")]
 	public class PlayerColorPaletteInfo : TraitInfo
 	{
 		[PaletteReference]

OpenRA.Game/Traits/Player/Shroud.cs

@@ -14,6 +14,7 @@ using System.Collections.Generic;
 
 namespace OpenRA.Traits
 {
+	[TraitLocation(SystemActors.Player | SystemActors.EditorPlayer)]
 	[Desc("Required for shroud and fog visibility checks. Add this to the player actor.")]
 	public class ShroudInfo : TraitInfo, ILobbyOptions
 	{