Explode unless told otherwise: a 2nd take on resolving ValueErrors

I took your advice and ran with the the idea of an optional project-level 'settings.DJAPPSETTINGS_STRICT'
It is not required. The default behavior is to consider it to be `True` and throw ValueErrors when confilcts are identified. 
 
If `settings.DJAPPSETTINGS_STRICT` is present and set to False then logging is used and errors are logged as Warnings.

When you have a chance, please have a look and let me know what you think.
Thanks.