Migrate Aphlict to Equatower

Summary:
Aphlict is the Phabricator notifications server.

It can be shared between several Phabricator instances.

Configure nginx to attach /ws/ to DevCentral, so we can serve the webstock in TLS too.

Fixes T661.
Fixes T660.
Fixes T797.

Test Plan:

• Click on the notications icon, "Connected."
• Fire a notification to catch it in the browser
• Visit https://devcentral.nasqueron.org/config/cluster/notifications/

Reviewers: dereckson

Reviewed By: dereckson

Maniphest Tasks: T661, T660, T797

Differential Revision: http://devcentral.nasqueron.org/D1676