Improved documentation of when QuerySet.exists() and .count() are a genuine optimization.
Improved documentation of when QuerySet.exists() and .count() are a genuine optimization.

Also fixed a typo.



git-svn-id: http://code.djangoproject.com/svn/django/trunk@11960 bcc190cf-cafb-0310-a4f2-bffc1f526a37

--HG--
extra : convert_revision : aef85e4bb83159674c2b79ea7d20de4678e62b7d

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