load_people should show account class

[adehnert]

If I'm going to get mail from groups/load_people.py every night with a list of changes, it would be nice if it included what sort of changes and/or the start or end account class (which would often explain why the change occurred --- if 30 class "2019" people show up, I can pretty safely guess that we're seeing so many changes because the frosh started to register their accounts).

[adehnert]

Fixed:

commit 161ce5fe2232ae99e85fda06a80df758d41d7de7
Author: Alex Dehnert <adehnert@mit.edu>
Date:   Mon Dec 24 02:30:45 2012 -0500

    Describe changes made by load_people (ASA-#192)
    
    groups/load_people.py outputs a summary of the changes it made --- the numbers
    of people processed, the usernames imported, etc.. However, it doesn't describe
    what *specific* changes occurred --- what fields were updated, what account
    class new users are in, etc.. This adds that data. In particular, showing the
    account classes of freshly created and destroyed users will probably help to
    notice any weird bursts of activity.