Instead of exploading when an different app ammends settings.py we log an error message. This will now play well with Mezzanine
ValueError reintroduced. It is the default, but if settings.DJAPPSETTINGS_STRICT is set to False errors are logged and the exception is not raised.
Remove logging configuration.
Merge pull request #3 from zlorf/master

Explode unless told otherwise: a 3rd take on resolving ValueErrors