settings must be imported from django.conf

[donatogr]

In several files (e.g. models/interfaces.py or models/managers.py) settings are imported with:

import settings

instead of:

from django.conf import settings

as stated in Django docs (https://docs.djangoproject.com/en/dev/topics/settings/#using-settings-in-python-code)

This will raise errors when used in complex environments, where settings are not located in the root directory (such as default Django 1.4+ projects).