Keeping Thumbnails up to date

[aibolit]

I have 300Gb archive of photos and every week new photos are added by various people.

I'd really like XnView to keep thumbnails database up to date.
For that i suggest (to be able to schedule it as automatic every day operation)
Add command line switch for already implemented (F12->Browser->Thumbnails->Cache->Add Folder) scanning specified folder recursivly for new photos