Allow using range-based for loops over YamlObject instances by
implementing iterators. New YamlObject::DictAdapter and
YamlObject::ListAdapter adapter classes are introduced to provide
different iterators depending on the object type.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Han-Lin Chen <hanlinchen@chromium.org>