rename Iterator getter to CursorIterator (#21)

src/Playback/PlaybackManager.ts

@@ -51,7 +51,7 @@ export class PlaybackManager implements IPlaybackParametersListener {
     private audioPlayer: IAudioPlayer<any>;
     private musicPartManager: MusicPartManager;
     private cursorIterator: MusicPartManagerIterator;
-    get Iterator(): MusicPartManagerIterator {
+    get CursorIterator(): MusicPartManagerIterator {
         return this.cursorIterator;
     }
     private playbackIterator: PlaybackIterator;