Remove Track.h from other headers

src/export/ExportMultiple.h

@@ -17,7 +17,6 @@
 #include <wx/listctrl.h>
 
 #include "Export.h"
-#include "../Track.h"
 #include "../Tags.h"       // we need to know about the Tags class for metadata
 
 class wxButton;
@@ -27,7 +26,9 @@ class wxRadioButton;
 class wxTextCtrl;
 
 class AudacityProject;
+class LabelTrack;
 class ShuttleGui;
+class TrackListIterator;
 
 class ExportMultiple : public wxDialog
 {
@@ -107,7 +108,7 @@ private:
    AudacityProject *mProject;
    TrackList *mTracks;           /**< The list of tracks in the project that is
                                    being exported */
-   TrackListIterator mIterator;  /**< Iterator used to work through all the
+   TrackListIterator *mIterator;  /**< Iterator used to work through all the
                                    tracks in the project */
    LabelTrack *mLabels;
    int mNumLabels;