FEAT: User sets privacy on Newts + Novelty groups

[India]

As a user, I want to set privacy defaults but be able to override them as needed, so that I can share only what I want, with whom I want to. I can share all or some of my content with classmates or students, or hide all or some of it from anyone I want (parents, rivals, the gubmint, employers).

Basic options

• I can choose whether all my newly created content will be public or private by default—that is, all my Newts and Novelty groups are either locked or open, until I set them otherwise. Changing this preference will not change previously created records; it will affect only new ones.
• I can toggle privacy for any Newt or Novelty. If I change privacy at the Novelty level, I can choose whether it affects all the Newts in that Novelty. (That is, as with Flickr albums, items in a collection can have different access settings; so I can make a subset of the list's contents public and have another more complete list that only I see.)

Nice-to-haves

• I have a nuclear privacy toggle option: make all my records private or public, all at once. This would come with a stern warning, and I should have to reenter my password to use this.
• I can create a Coven/Flight/Knot/Sabbat of other registered LearnWitch users (e.g., a study group or class) and share my whole account, a Newt, or a Novelty only with that group.