core: add deletion of items to media-db
core: add deletion of items to media-db

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