Add a helper for iterating an object's map heirachy
Add a helper for iterating an object's map heirachy

This patch introduces an ObjectMapHierachy adapter, for working with the
heirachy all at once. It adds a new iterator as well, so you can now
write:

  for (const OjectMap& m : object->mapHierachy())
    // do something

Signed-off-by: Robert Young <42c59959a3f4413d6a1b4d7b4f99db457d199e49@gmail.com>

jduimovich/Base9,jduimovich/Base9,youngar/Base9,youngar/Base9,youngar/Base9