Small Changes, add CAS login to /admin

* Changed settings.DEBUG --> settings.ENFORCING
* Created new URL endpoint /cas_admin that will handle logging a user in to
  /admin, rather than require Username/Password entry.
* atmosphere/wsgi.py safegards against failued initialize of newrelic
* Add check_quota to reboot_instance
URL Change: /cas_admin --> /admin_login
Merge branch 'abyssinian-nightjar' of https://github.com/iPlantCollaborativeOpenSource/atmosphere into abyssinian-nightjar