Add ability to export tileset tiles image

include/ui/tileseteditor.h

@@ -76,6 +76,10 @@ private slots:
 
     void on_comboBox_layerType_activated(int arg1);
 
+    void on_actionExport_Primary_Tiles_Image_triggered();
+
+    void on_actionExport_Secondary_Tiles_Image_triggered();
+
 private:
     void closeEvent(QCloseEvent*);
     void initMetatileSelector();

include/ui/tileseteditortileselector.h

@@ -25,6 +25,8 @@ public:
     QList<Tile> getSelectedTiles();
     void setExternalSelection(int, int, QList<Tile>);
     QPoint getTileCoordsOnWidget(uint16_t);
+    QImage buildPrimaryTilesIndexedImage();
+    QImage buildSecondaryTilesIndexedImage();
 
 protected:
     void mousePressEvent(QGraphicsSceneMouseEvent*);