Update Optimisation for Windows + Add Qt to AboutBox

sources/mainwindow.cpp

@@ -51,6 +51,7 @@ void MainWindow::init() {
         Welcome w(week_template);
         w.exec();
         week_template = w.get_result();
+        saveLoaded = true;
     }
     if (saveLoaded) {
         set_date_to_now();
@@ -139,6 +140,7 @@ void MainWindow::save_to_file() {
         f->write(doc.toJson());
         f->close();
     }
+    delete f;
 }
 
 void MainWindow::compute_week_number(const QDateTime &dt) {