use an element buffer for rendering

src/mesh_processor.h

@@ -10,17 +10,13 @@
 class MeshProcessor : public QObject {
 	Q_OBJECT
 
-	std::vector<HalfedgeHandle> holes;
-
-	// friend class MeshProcessorPainter;
-
 public:
 	MyMesh mesh;
+	std::vector<HalfedgeHandle> holes;
 
 	MeshProcessor(const QString &path);
 
 public slots:
-	void highlightHoles();
 	void fillHoles();
 };