Fixed #17131 - Added per object permission notes to docs.
Fixed #17131 - Added per object permission notes to docs.

Thanks dchandek for the suggestion and mateusgondim for the patch.

Backport of 8d3e501502c308cbdd3cc95b62ace0fe11d373ab from master

riklaunim/django-custom-multisite,riklaunim/django-custom-multisite,riklaunim/django-custom-multisite