void Menu::addMenuItem(std::string labelIn)
{
    if (top->label == "") {
        top->label = labelIn;
        top->next = top;
        top->previous = top;
    }
    else {
        MenuItem *newItem = new MenuItem;

        newItem->next = top;
        newItem->previous = top->previous;
        top->previous->next = newItem;
        top->previous = newItem;
        newItem->label = labelIn;
        top = newItem;
    }
}