core: Only allow importing to our own items
core: Only allow importing to our own items

Only allow importing contents to URIs belonging to our own items.

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