Updated to use Qt6; Created initial structure of the viewer with OpenGL widget

src/qtviewer/main.cpp

@@ -1,24 +1,12 @@
-
+#include "MainWindow.h"
+
 #include <QApplication>
-#include <QString>
-#ifndef QT_NO_OPENGL
-#include <QGLFormat>
-#endif
 
-#include "mainwindow.h"
-
-int main(int argc, char **argv)
+int main(int argc, char *argv[])
 {
-    QApplication app(argc, argv);
-
-	//QGLViewer viewer;
-
-   // Restore the previous viewer state.
-   //viewer.restoreStateFromFile();
-
-    MainWindow window;
-    //window.openFile("	");
+  QApplication app(argc, argv);
 
+  MainWindow window;
   window.show();
 
   return app.exec();