change map format to remove redundant crap

OpenRA.FileFormats/Map/ActorReference.cs

@@ -12,13 +12,14 @@ namespace OpenRA.FileFormats
 {
 	public class ActorReference
 	{
-		public readonly string Id;
+		public string Id { get; private set; }
 		public readonly string Type;
 		public readonly int2 Location;
 		public readonly string Owner;
 		
-		public ActorReference(MiniYaml my)
+		public ActorReference( string id, MiniYaml my)
 		{
+			Id = id;
 			FieldLoader.Load(this, my);
 		}
 		

OpenRA.FileFormats/Map/Map.cs

@@ -132,7 +132,7 @@ namespace OpenRA.FileFormats
 			{
 				foreach (var kv in yaml["Actors"].Nodes)
 				{
-					var a = new ActorReference(kv.Value);
+					var a = new ActorReference(kv.Key, kv.Value);
 					Actors.Add(a.Id, a);
 				}
 			}
@@ -172,7 +172,7 @@ namespace OpenRA.FileFormats
 
 			root.Add("Actors",
 				new MiniYaml(null, Actors.ToDictionary(
-					a => "ActorReference@{0}".F(a.Key),
+					a => "{0}".F(a.Key),
 					a => FieldSaver.Save(a.Value))));
 			
 			root.Add("Waypoints", MiniYaml.FromDictionary<string, int2>(Waypoints));