Clean up a system so it's more like a freshly installed one

 Over time, a computer system tends to get cluttered. For example,
 software packages that are no longer needed can be uninstalled.
 When the system is upgraded from release to release, it may miss
 out on configuration tweaks that freshly installed systems get.
 .
 Computer Janitor is an application to fix these kinds of problems.
 It attempts to find software packages that can be removed, and
 tweaks the system configuration in useful ways.
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 This is the command line version.