Fixed #13316 -- Added clarifying note about cross-database relations.
Fixed #13316 -- Added clarifying note about cross-database relations.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@13178 bcc190cf-cafb-0310-a4f2-bffc1f526a37

--HG--
extra : convert_revision : 45d1d33f78d0755463af5f89d3a7dc30b435ed08

heracek/django-nonrel,adieu/django-nonrel,adieu/django-nonrel,heracek/django-nonrel,heracek/django-nonrel,adieu/django-nonrel