Make outgoing email subject lines use "SlideAtlas" instead of domain name
Send an email to site administrators when a new user is created
Display a more helpful welcome notification to new users
Merge branch 'new-user-notify'

* new-user-notify:
  Display a more helpful welcome notification to new users
  Send an email to site administrators when a new user is created
  Make outgoing email subject lines use "SlideAtlas" instead of domain name