More request changes

[swilcox]

• added email field for publish request items
• added email templates (both plain and html) for publish request:
  • received
  • accepted
  • rejected
• fixed issue with celery (since some of the above now launches using celery async)
• moved existing email templates to a common "/email" sub-directory for consistency

Issues resolved:

27

So note:

• you must manage.py migrate after pulling in the new source code so that the new email field is added to the database
• you must use celery now for async handling of email things
• default config uses celery with redis (so redis needs to be running)
• you have to create a celery worker with the manage.py celery worker command (see celery django documentation for more info on available options).