Added multiple track export feature.

Here is the patchset for my multiple track export feature. It works now
the way I originally envisioned.

For example, after I export tracks on my little song, I see this in the
directory I created:

devin@devin-studio:~/lmms/projects/fff$ ls
0_Defaultpreset.wav  3_Defaultpreset.wav      6_csidSouwav.wav
1_Defaultpreset.wav  4_spacenoiseswavwav.wav  7_HHOPENwav.wav
2_Defaultpreset.wav  5_csidkickwav.wav        8_HHOPENwav.wav

Each instrument or sample track is exported individually, regardless of
whether in its own song track or playing as part of a BB track. The
name is taken from either the song track name or from the BB track name.
My goal was to get the tracks individually exported, so that I could
combine them with other tracks in Ardour.

Signed-off-by: Tobias Doerffel <tobias.doerffel@gmail.com>

include/export_project_dialog.h

@@ -28,17 +28,17 @@
 #define _EXPORT_PROJECT_DIALOG_H
 
 #include <QtGui/QDialog>
-
+#include <vector>
 #include "ui_export_project.h"
 
-class ProjectRenderer;
+#include "ProjectRenderer.h"
 
 
 class exportProjectDialog : public QDialog, public Ui::ExportProjectDialog
 {
 	Q_OBJECT
 public:
-	exportProjectDialog( const QString & _file_name, QWidget * _parent );
+	exportProjectDialog( const QString & _file_name, QWidget * _parent, bool multi_export );
 	virtual ~exportProjectDialog();
 
 
@@ -50,12 +50,20 @@ protected:
 private slots:
 	void startBtnClicked( void );
 	void updateTitleBar( int );
-
+	void render(ProjectRenderer* renderer);
+	void multi_render();
+	ProjectRenderer* prep_render();
+	void pop_render();
+    void accept();
 
 private:
 	QString m_fileName;
-	ProjectRenderer * m_renderer;
-
+	QString m_dirName;
+	std::vector<ProjectRenderer*> m_renderers;
+	bool m_multi_export;
+	std::vector<track*> m_unmuted;
+	ProjectRenderer::ExportFileFormats m_ft;
+	std::vector<track*> m_to_render_vec;
 } ;
 
 #endif

include/song.h

@@ -207,7 +207,8 @@ public slots:
 	void resumeFromPause();
 
 	void importProject();
-	void exportProject();
+	void exportProject(bool multiExport=false);
+	void exportProjectTracks();
 
 	void startExport();
 	void stopExport();