New permission "change watcher settings"

I would like to have the ability to lock down the watcher settings. I think the defaults I've set will satisfy 99% of my users, and the settings screen will only cause confusion. In my opinion, and for my site. I've created a patch that adds a new permission "change watcher settings". The Settings tab on My Watched Posts will only be shown to people who have this permission. Feel free to modify to suit, but I hope you'll consider it. (And keep up the great work, this is a good module).