Log Message:
Update to 20181028. Changes:

- CERTFILE needs to be set early enough for sslserver. Move it to rc.d.
  UCSPITLS is application-specific and can stay in the CDB.
- Add PYMSGAUTH_TOLERATE_UNCONFIGURED to the CDB.
- Switch qmailpop3d from tcpserver+qmail-popup to sslserver+authup.
  Set UCSPITLS in the CDB to require STLS before USER/PASS.
- Specify a few new required_files.
- Point more precisely at the need to inspect alias/.qmail-*.