Bug#655426: "can no longer be downloaded" documentation nicety

[jidanni@jidanni.org]

Package: apt
Version: 0.8.15.9
Severity: wishlist
File: /usr/share/man/man8/apt-get.8.gz

       autoclean
           Like clean, autoclean clears out the local repository of retrieved
           package files. The difference is that it only removes package files
           that can no longer be downloaded ...

Mention
 ... via apt, (e.g., a new version of the package is available, even
 though one can still download it via e.g., wget.)

Man aptitude could mention that too.