R1:9a7ad972cd26

Refactoring of the Aphlict server

Summary: Tidy the Aphlict server by splitting the functionality into two main modules, `AphlictClientServer` and `AphlictAdminServer. There is still further tidying that could be done here, but I feel that this puts us in a much better place.

Test Plan: Sent notifications via `/notification/status/`.

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley, #blessed_reviewers

Subscribers: Korvin, epriestley

Differential Revision: https://secure.phabricator.