What if close election between moment of start and moment of last email sent?

[kfogel]

What happens if you close an election between the moment it is started and the moment the last ballot email is sent to voter? That is, in controllers/default.py between start() and start_callback()?

In theory, the code now handles it correctly since commit 330ed3d. But this has not actually been tested. We could easily test it with a delay loop to slow down the email sending (or logging to console), too.