Improved model validator to make sure prepopulate_from is a list or tuple
Improved model validator to make sure prepopulate_from is a list or tuple

git-svn-id: 4f9f921b081c523744c7bf24d959a0db39629563@617 bcc190cf-cafb-0310-a4f2-bffc1f526a37

hugs/django,sam-tsai/django-old,mitsuhiko/django,skevy/django,django-nonrel/django-nonrel,jamespacileo/django-france,rawwell/django,alex/django-old,bfirsh/django-old,skevy/django,alex/django-old,t11e/django,bfirsh/django-old,dcramer/django-compositepks,skevy/django,dcramer/django-compositepks,disqus/django-old,django-nonrel/django-nonrel,disqus/django-old,Smarsh/django,Instagram/django,Smarsh/django,Smarsh/django,jamespacileo/django-france,sam-tsai/django-old,Instagram/django,Smarsh/django,rawwell/django,alex/django-old,django-nonrel/django-nonrel,disqus/django-old,mitsuhiko/django,sam-tsai/django-old,dcramer/django-compositepks,hugs/django,sam-tsai/django-old,mitsuhiko/django,rawwell/django,jamespacileo/django-france,bfirsh/django-old,t11e/django,t11e/django,Instagram/django,hugs/django