Added a check to see if the model has been saved, an assert consistent with the Django ORM base model, to the delete methods of ImageModel and PhotoEffect.
Added a check to see if the model has been saved, an assert consistent with the Django ORM base model, to the delete methods of ImageModel and PhotoEffect.

praekelt/django-photologue,unomena/django-photologue,glogiotatidis/django-photologue-ng,strakh/django-photologue,WebReply/django-photologue,praekelt/django-photologue