Make AOLserver and PostgreSQL all follow same case, clean up compat matrix some, add pg7.4 as untested for 5.0.0 (Guan Yang has installed on 7.4 so it seems to work), add comment on 7.4 and 9i status, remove unused version of compatability.xml
the upgrade failed because notification_user_map constraint notif_user_map_notif_id_fk needed the pk on notifications_bak, now drops it and recreates it after the table is reloaded