change the way, size, height, OID, etc is entered in the DB: do it via the Entity...

change the way, size, height, OID, etc is entered in the DB: do it via the Entity interface and not via manual SQL. with manual SQL, the entity becomes out of sync w/ data in the DB and this is bad. It's not as fast as the manual SQL, but more consistent and nicer. also move the update override method that sets content that has this media item attached to EntityUploadedMedia so all media types can take advantage of it