[For 1.8] Prune old PMs + optimize DB v1.0.0

[Darkrad]

I see, so I want to tell my users 'if you don't want your PMs to not removed automatically, you can basically create a new PM folder and move them to there, if you do that your PM won't be removed'   and if user creates another folder (folder 5) and moves, this plugin doesn't remove it if I understood correctly?