Obsolete page cleanup

Hi gang, We have a few obsolete pages floating around that I can't really imagine anyone needing at this point: 1. cvsup.php: hasn't been relevant since we moved to SVN, let alone Git. 2. mirroring-stats.php: very out of date, and the mirrorkit.tgz it refers to hasn't been around for a long time. If anyone particularly wants one or more of these to survive, speak now or forever hold your peace. (Or revert my commit when I remove them next week.) Also: security-note.php might be worth reviewing, too. It does date from 2005. Thanks, Adam