Update file mod date-time of archives to contents' latest

[TomTrottier]

For ZIP, 7Z, RAR, and other archives, allow updating the "Modified" timestamp of the archive to the the latest timestamp of any enclosed file.

Often, file activities change the "modified" date, yet the underlying files remain the same.
Allowing users to specify updating the the timestamp of the archive to match the latest timestamp of contained files would be helpful in deciding which archive is actually the most current.

Thanks, tOM