Changed explicit User relation to configurable setting

[niktto]

because hardcoding User in a ForeignKey stops people from specifing
alternative user models using settings.AUTH_USER_MODEL

This fix silences fields.E301 error raised by Django system check (https://docs.djangoproject.com/en/1.8/ref/checks/#related-fields) for users that, for example, use django-authtools or declare own user models based on django.contrib.auth.models.AbstractUser.

Thanks and best regards :),
Marek

[funkaoshi]

This breaks in Django 1.4. The easy fix here is to check if AUTH_USER_MODEL is an attribute of settings, and if it is not continue to import users.

[niktto]

Sorry for not noticing this @funkaoshi , I'll fix my PR and notify you when it's ready. Thanks! :)

[funkaoshi]

@niktto No problem. Thanks for contributing. If you search around there are lots of examples of people doing what you are trying to do. We might need to change a migration as well. @emintham has been looking at this stuff as well as we look to upgrade our app to 1.7.

[niktto]

As for migrations, I can see that here https://github.com/sdelements/django-security/blob/master/security/migrations/0001_initial.py#L11 they are properly set to use User model specified in settings (only in new migrations, so there will be no problem with Django 1.4).

I use (my fork for now) django-security in Django 1.8 app with custom user model (django-authtools) and migrations work like a charm.

[funkaoshi]

@niktto Sorry We haven't looked at this in ages! Will bug someone here to review and get this merged.

[shawngustaw]

@funkaoshi +1