core: Make sure parent container is alive
core: Make sure parent container is alive

If the item does not carry a reference to its parent, we set it to make
sure the container is still alive if we run in the auto-removal
timeout.

Pelagicore/Media-Manager-Rygel-patched,jku/rygel,Tarnyko/rygel,Pelagicore/Media-Manager-Rygel-patched,GNOME/rygel,GNOME/rygel,jku/rygel,GNOME/rygel,Tarnyko/rygel,Pelagicore/Media-Manager-Rygel-patched