Binary package “upgrade-system” in ubuntu precise

command for upgrading and sanitizing a Debian system

 Upgrade-system offers a convenient way to keep a Debian system up-to-date,
 yet free from accumulated cruft such as obsolete libraries.
 It is particularly useful on systems that mix packages from different
 releases (stable/testing/unstable) and on desktop systems where packages
 are frequently installed or removed according to evolving user tastes.
 By default, it is configured to purge all packages that are not listed
 as another package's dependency. Less drastic settings are possible by
 editing /etc/upgrade-system.conf(5).