Document replacement of `self.request.user`
We are using custom LDPViewSet to provide endpoints delivering resources based on current user preferences.
It seems to happen that a check like the following:
.exclude(submitter=self.request.user) in a custom LDPViewSet does not actually exclude the current user from the result querySet.
I suppose it's because we are not using the default User class anymore, so
self.request.user is a wrong check.