clean up of inconsistency between old and new installations -- -- Since many years, new installations are created with "Registered -- Users" (object_id -2) having object_type as "application_group" and -- the context id of the main subsite (see -- acs-kernel/sql/postgresql/acs-install.sql). -- -- However, it seems as if some prior upgrade scripts have not cared -- sufficiently to update all installation correctly (some have still -- "group", some have no context_id set). This upgrade script tries to -- bring everything in sync such that "newer" and "older" -- installations behave the same. --