Take list of groups off of front page

[nmorduch]

When this is used by people who don't know each other and might not have set a password, they're not going to want their group listed on that page. I think it will be useful to us to have a page with a list of groups so that we can test and troubleshoot, but that list should not be available to the public.

[nmorduch]

Maybe we don't need to do this for very initial testing, though, since it means probably making a bit of an admin. Hm.