Implement AssetHelper.deleteStaleAssets().

src/lime/tools/AssetHelper.hx

@@ -191,6 +191,25 @@ class AssetHelper
 		return manifests;
 	}
 
+	public static function deleteStaleAssets(project:HXProject, targetDirectory:String):Void
+	{
+		var newAssets = [for (asset in project.assets) asset.targetPath];
+
+		var recordFile:String = targetDirectory + "/.assets";
+		if (FileSystem.exists(recordFile))
+		{
+			for (oldAsset in File.getContent(recordFile).split("\n"))
+			{
+				if (oldAsset.length > 0 && newAssets.indexOf(oldAsset) < 0)
+				{
+					System.deleteFile(targetDirectory + "/bin/" + oldAsset);
+				}
+			}
+		}
+
+		File.saveContent(recordFile, newAssets.join("\n"));
+	}
+
 	private static function getAssetData(project:HXProject, pathGroups:Map<String, Array<String>>, libraries:Map<String, Library>, library:String,
 			asset:Asset):Dynamic
 	{

src/lime/tools/PlatformTarget.hx

@@ -103,6 +103,8 @@ class PlatformTarget
 			// AssetHelper.processLibraries (project, targetDirectory);
 			// #end
 			update();
+
+			AssetHelper.deleteStaleAssets(project, targetDirectory);
 		}
 
 		if (command == "build" || command == "test")