generateorders has misleading output

[kousu]

Actual Behaviour

As found in #828 :

$ /usr/bin/docker exec souschef_web_1 python src/manage.py generateorders 2018-02-27 --days 100
 
75 orders created on 2018-02-27: to be delivered on 2018-02-27.
...

but I checked the frontend, and the orders weren't created as far as I can tell: I would expect created orders to be in the Ordered state, but the Ordered state was empty for 2018-02-27, and instead most orders were in Delivered (due to manage.py setordersdelivered).

I'm guessing that whoever wrote generateorders wisely made it idempotent. That's the only way generated --days 100 ahead every night could be safe. I applaud this. But the logging statement is misleading.

Expected Behaviour

manage.py generateorders should accurately describe what it's doing to the database. It's a pretty powerful command and it's scary to run it without being able to see inside it. I want the output to be something more like

2018-02-27T21:00:00: 75 orders on to be delivered on 2018-02-27 (74 existing, 1 created).