R1:001f76cbaae7

Projects - tighten up a few things

Summary:
Fixes T2675, T2676.

- when the last person leaves a project it is archived.
- a script to archive all memberless projects
- better feed stories for the various policy edits you can do
- phriction pages are also moved as you rename projects

Test Plan: edited some projects and noted reasonable feed stories. ran script against test data and it worked! left a last man standing project and it archived. renamed a project to "a" then "b" then "a" (etc) and it…