Rework player palette loading.

OpenRA.Game/Traits/TraitsInterfaces.cs

@@ -194,6 +194,7 @@ namespace OpenRA.Traits
 	public interface IInaccuracyModifier { int GetInaccuracyModifier(); }
 	public interface IPowerModifier { int GetPowerModifier(); }
 	public interface ILoadsPalettes { void LoadPalettes(WorldRenderer wr); }
+	public interface ILoadsPlayerPalettes { void LoadPlayerPalettes(WorldRenderer wr, string playerName, HSLColor playerColor, bool replaceExisting); }
 	public interface IPaletteModifier { void AdjustPalette(IReadOnlyDictionary<string, MutablePalette> b); }
 	public interface IPips { IEnumerable<PipType> GetPips(Actor self); }
 	public interface ITags { IEnumerable<TagType> GetTags(); }