Fixed #22369 -- Added count parameter to assertTemplateUsed
Fixed #22356 -- Added a check to make sure unique_together fields are local.
Fixed #18773 -- Add logging for template variable resolving

Added a django.template logger with a default null handler.  Added
logging if there is an exception while resolving variables in a
template. Added corresponding tests and updated logging
documentation.
Merge branch 'master' of git://github.com/django/django into ticket_18773