Help dialogs are now not modal (fixed #1655)

src/gui/TutorialDialog.cpp

@@ -58,6 +58,7 @@ TutorialDialog::TutorialDialog(QString tutorial, QWidget *parent) :
     showPage(currentPage);
 
     wfl->registerTutorialViewing(tutorial);
+    this->setWindowFlags(this->windowFlags() | Qt::WindowMinimizeButtonHint);
 }
 
 void TutorialDialog::resizeEvent(QResizeEvent *)