Remove some unneeded #includes and forward declarations

src/import/ImportFFmpeg.cpp

@@ -28,7 +28,6 @@ Licensed under the GNU General Public License v2 or later
 #include <wx/wxprec.h>
 
 #include "../FFmpeg.h"      // which brings in avcodec.h, avformat.h
-#include "../WaveClip.h"
 #ifndef WX_PRECOMP
 // Include your minimal set of headers here, or wx.h
 #include <wx/window.h>

src/import/ImportFLAC.cpp

@@ -42,7 +42,6 @@
 #include "ImportPlugin.h"
 
 #include "../Tags.h"
-#include "../WaveClip.h"
 #include "../prefs/QualityPrefs.h"
 #include "../widgets/ProgressDialog.h"
 

src/import/ImportLOF.cpp

@@ -84,12 +84,10 @@
 #include "../WaveTrack.h"
 #include "ImportPlugin.h"
 #include "Import.h"
-#include "../NoteTrack.h"
 #include "../Project.h"
 #include "../ProjectHistory.h"
 #include "../ProjectManager.h"
 #include "../ProjectWindow.h"
-#include "../FileFormats.h"
 #include "../Prefs.h"
 #include "../widgets/AudacityMessageBox.h"
 #include "../widgets/ProgressDialog.h"

src/import/ImportPCM.cpp

@@ -36,7 +36,6 @@
 
 #include "sndfile.h"
 
-#include "../WaveClip.h"
 #include "../ShuttleGui.h"
 
 #include "../prefs/QualityPrefs.h"