lint check player palette reference

and tell which actor is affected when a problem is found

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

@@ -21,11 +21,11 @@ namespace OpenRA.Mods.Common.Traits
 	{
 		[FieldLoader.Require]
 		[Desc("The prefix for the resulting player palettes")]
-		public readonly string BaseName = null;
+		[PaletteDefinition(true)] public readonly string BaseName = null;
 
 		[FieldLoader.Require]
 		[Desc("The name of the player palette to base off.")]
-		public readonly string BasePalette = null;
+		[PaletteReference(true)] public readonly string BasePalette = null;
 
 		[Desc("Allow palette modifiers to change the palette.")]
 		public readonly bool AllowModifiers = true;

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

@@ -16,7 +16,7 @@ namespace OpenRA.Mods.Common.Traits
 {
 	class PlayerPaletteFromCurrentTilesetInfo : ITraitInfo
 	{
-		[FieldLoader.Require, PaletteDefinition]
+		[FieldLoader.Require, PaletteDefinition(true)]
 		[Desc("internal palette name")]
 		public readonly string Name = null;
 		[Desc("Map listed indices to shadow.")]