Added check to the staticfiles app to make sure the STATIC_ROOT setting isn't accidentally added to the STATICFILES_DIRS setting. Thanks for the suggestion, SmileyChris and harijay.
Added check to the staticfiles app to make sure the STATIC_ROOT setting isn't accidentally added to the STATICFILES_DIRS setting. Thanks for the suggestion, SmileyChris and harijay.

git-svn-id: 4f9f921b081c523744c7bf24d959a0db39629563@15376 bcc190cf-cafb-0310-a4f2-bffc1f526a37

disqus/django-old,disqus/django-old,jamespacileo/django-france,django-nonrel/django-nonrel,mitsuhiko/django,Instagram/django,Instagram/django,jamespacileo/django-france,skevy/django,mitsuhiko/django,jamespacileo/django-france,skevy/django,Instagram/django,django-nonrel/django-nonrel,mitsuhiko/django,skevy/django,django-nonrel/django-nonrel,disqus/django-old