edx-west: toggle carnegie institute to prod
notifier config improvements: db dir, email vars

- specify notifier_db_dir as a setting.  Had previously just stuck
  under $HOME, but Jim preferred as a distinct setting.

- pass through email settings env variables

- plumb through django's EMAIL_USE_TLS setting.  Required to be
  able to send mail using Amazon SES.  They speak smtp, but only
  over TLS.
Merge pull request #286 from edx/sef/fix-notifier-sqlite-location

Notifier config improvements: db dir, email vars
Merge pull request #285 from edx/carnegie-no-auth

edx-west: toggle carnegie institute to prod
edx-west prod: don't install notifiers yet

The notifier isn't ready yet, needs theming to be done before it can be
installed.
Merge pull request #288 from edx/sef/edx-west-no-notifier-on-workers-yet

edx-west prod: don't install notifiers yet
Slight refactor to make this more like edxapp and reuse nginx role
Merge remote-tracking branch 'upstream/carsongee/xserver-nginx-fix' into mitx-additions