Updates to Debian scripts:

  - debconf for smtp_server and mail_sender
  - cgi is now .../cgi-bin/disorder rather than .../cgi-bin/disorder/disorder
  - auto setup guest login if possible
  - auto remove obsolete trust/allow after first server start
    (specifically, they are commented out so the user can put them
    back if things went awry.)

Things are still rather broken but they're getting there...