Fixed performance issue in offer dashboard detail page
Fixed performance issue in offer dashboard detail page

There was an N-query issue while displaying all orders
the offer was applied to.

okfish/django-oscar,solarissmoke/django-oscar,django-oscar/django-oscar,solarissmoke/django-oscar,sasha0/django-oscar,okfish/django-oscar,michaelkuty/django-oscar,sasha0/django-oscar,john-parton/django-oscar,sasha0/django-oscar,django-oscar/django-oscar,sonofatailor/django-oscar,john-parton/django-oscar,okfish/django-oscar,sasha0/django-oscar,solarissmoke/django-oscar,anentropic/django-oscar,michaelkuty/django-oscar,solarissmoke/django-oscar,okfish/django-oscar,michaelkuty/django-oscar,anentropic/django-oscar,michaelkuty/django-oscar,john-parton/django-oscar,django-oscar/django-oscar,anentropic/django-oscar,sonofatailor/django-oscar,sonofatailor/django-oscar,django-oscar/django-oscar,anentropic/django-oscar,sonofatailor/django-oscar,john-parton/django-oscar