Ensure LuaValues are disposed.

Adding in these missing calls prevents these instances from having to be finalized.

OpenRA.Mods.Common/Scripting/Global/PlayerGlobal.cs

@@ -28,12 +28,7 @@ namespace OpenRA.Mods.Common.Scripting
 		[Desc("Returns a table of players filtered by the specified function.")]
 		public Player[] GetPlayers(LuaFunction filter)
 		{
-			return Context.World.Players
-				.Where(p =>
-				{
-					using (var f = filter.Call(p.ToLuaValue(Context)))
-						return f.First().ToBoolean();
-				}).ToArray();
+			return FilteredObjects(Context.World.Players, filter).ToArray();
 		}
 	}
 }