Removed prefetch_related('source') from all_images
Merge branch 'master' of github.com:opps/opps

* 'master' of github.com:opps/opps:
  organization validation slug source in channel
  Fix bug start with on check channel slug
  remove code on comment in channel models class
  Remove validate `slug exist in domain` channel, check in Slugged class
  Fix bug, not rename channel on save parent in self
  user object site (self) to get template folder in generic base view
  Fix validate slug, add channel parent in filter, class Slugged