MatVGL put into work.

#include "matvglapp.h"
#include "matvglwindow.h"

using namespace MatVGL;

int main(int argc, char *argv[]) {
  DesktopApp *app = new DesktopApp(argc, argv);

  DesktopWindow *window = new DesktopWindow(
      DesktopWindow::Title("Test Window"), DesktopWindow::Position::Center,
      DesktopWindow::Width(800), DesktopWindow::Height(600),
      DesktopWindow::Mode::Fixed);

  window->start();

  int executionValue = app->exec();
  delete window;
  delete app;
  app = nullptr;
  window = nullptr;

  return executionValue;
}