Begin generalizing Aphlict server to prepare for clustering/sensible config file

Summary:
Ref T10697. Currently, aphlict takes a ton of command line flags to configure exactly one admin server and exactly one client server.

I want to replace this with a config file. Additionally, I plan to support:

• arbitrary numbers of listening client ports;
• arbitrary numbers of listening admin ports;
• SSL on any port.

For now, just transform the arguments to look like they're a config file. In the future, I'll load from a config file instead.

This greater generality will allow you to do stuff like run separate HTTP and HTTPS admin ports if you really want. I don't think there's a ton of use for this, but it tends to make the code cleaner anyway and there may be some weird cross-datacneter cases for it. Certainly, we undershot with the initial design and lots of users want to terminate SSL in nginx and run only HTTP on this server.

(Some sort-of-plausible use cases are running separate HTTP and HTTPS client servers, if your Phabricator install supports both, or running multiple HTTPS servers with different certificates if you have a bizarre VPN.)

Test Plan: Started Aphlict, connected to it, sent myself test notifications, viewed status page, reviewed logfile.

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T10697

Differential Revision: https://secure.phabricator.com/D15700