When assigning properties, we were relying on the JSON serialization
code to wrap strings in double-quotes ("). JsonValue::to_string() does
not wrap string values, so what we want here is serialized(). :^)
The basic idea is that you would use it like this:
MyWidget::MyWidget(GWidget* parent)
: GWidget(parent)
{
m_ui = new UI_MyWidget;
set_main_widget(m_ui->main_widget);
...
}