Restrict attendee count to STATS access

AnthroCon keeps their attendee count under wraps until closing ceremonies - for that reason, we need to be able to hide it from all but certain admin accounts. I removed it from the attendee list and restricted the summary page to only accounts with Analytics access.
Makes sense, but for what it's worth, if someone has ``PEOPLE`` access they can look at the attendee page.  Since there are 100 attendees per page, you can look at the number of pages and multiply by 100 to get the count.  We also display the checked in number on the top of that page.

The whole ``STATS`` access was intended to be a *lower* level of access than ``PEOPLE`` so that we could let people look this stuff up without being able to e.g. add new people to the database.