(including the one that comes with dpkg >= 1.10).
* Protect the call to add_secured by a stamp file. Closes: #147105
* Provide a customised isolinux image. We don't need to
recommend syslinux now.
SECURED environment variable. It is *disabled* by default
(thanks to jgg who doesn't want to correct apt even if he
proposed the current scheme)
* Priority optional (same than in the overrides)
Raphaël Hertzog