Let's add some helpers to make accessing simple configuration values
simpler. The helpers are used in the followup patches.
GlobalConfiguration::option ensures that no value is returned rather
than a value of YamlObject::empty.
Signed-off-by: Milan Zamazal <mzamazal@redhat.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>