Revision 576

   * Both dialog and whiptail now support --nocancel, which the dialog
     frontend will use now if a cancel button is not appropriate.
     Closes: #67419
   * Reluctantly brought back a *temoporary* dependancy on perl-5.6 until
     it gets it act in order. Closes: #79571 (Debian *cannot* be released
     while debconf has this bogus dependancy.)