Tool for automated cleaning of ${prefix}/var/distfiles

[Jeremy Lavergne]

The version counter can go back in time, this is why we have epoch ;-)

> Granted, but this is true only for the code corresponding to the current version of the Portfile, not outdated code, that cannot be re-installed anyway, since, as Ryan pointed out in a previous message following a bug of mine, the version counter cannot go back in time…