add settings icon,

set ogl verison to 2.0 to make it compatible with more PCs

QtMeshViewer/Source/MainWindow.cpp

@@ -29,6 +29,9 @@ MainWindow::MainWindow(QWidget *parent)
 
 	QSurfaceFormat format;
 	format.setDepthBufferSize(24);
+	format.setMajorVersion(2);
+	format.setMinorVersion(0);
+	format.setProfile(QSurfaceFormat::NoProfile);
 	QSurfaceFormat::setDefaultFormat(format);
 
 	setupWidgets();