Post data to the Aphlict server in JSON encoded form.

Summary:
Ref T4324. Currently, notifications data is `POST`ed to the Aphlict server in the `application/x-www-form-urlencoded` format. This works fine for simple data but is problematic for nested data. For example:

```lang=php
array(
  'data' => array(
    'key'  => '6021329908492455737',
    'type' => 'PhabricatorNotificationAdHocFeedStory',
  ),
  'subscribers' => array(
    'PHID-USER-y7ofqm276ejs62yqghge',
  ),
);
```

Is encoded as `data%5Bkey%5D=6021329908492455737&data%5Btype%5D=PhabricatorNotificationAdHocFeedStory&subscribers%5B0%5D=PHID-USER-y7ofqm276ejs62yqghge`. This string is then (incorrectly) decoded by `querystring.parse` as:

```lang=javascript
> querystring.parse('data%5Bkey%5D=6021329908492455737&data%5Btype%5D=PhabricatorNotificationAdHocFeedStory&subscribers%5B0%5D=PHID-USER-y7ofqm276ejs62yqghge');
{ 'data[key]': '6021329908492455737',
  'data[type]': 'PhabricatorNotificationAdHocFeedStory',
  'subscribers[0]': 'PHID-USER-y7ofqm276ejs62yqghge' }
```

Test Plan: Sent test notifications from `/notification/status/` and verified that the notifications still worked.

Reviewers: #blessed_reviewers, epriestley

Reviewed By: #blessed_reviewers, epriestley

Subscribers: epriestley, Korvin

Maniphest Tasks: T4324

Differential Revision: https://secure.phabricator.com/D9386

Author: joshuaspence

src/applications/notification/client/PhabricatorNotificationClient.php

@@ -2,7 +2,7 @@
 
 final class PhabricatorNotificationClient {
 
-  const EXPECT_VERSION = 3;
+  const EXPECT_VERSION = 4;
 
   public static function getServerStatus() {
     $uri = PhabricatorEnv::getEnvConfig('notification.server-uri');
@@ -28,7 +28,7 @@ public static function getServerStatus() {
   public static function postMessage(array $data) {
     $server_uri = PhabricatorEnv::getEnvConfig('notification.server-uri');
 
-    id(new HTTPSFuture($server_uri, $data))
+    id(new HTTPSFuture($server_uri, json_encode($data)))
       ->setMethod('POST')
       ->setTimeout(1)
       ->resolvex();

support/aphlict/server/aphlict_server.js

@@ -63,7 +63,6 @@ if (process.getuid() !== 0) {
 var net = require('net');
 var http  = require('http');
 var url = require('url');
-var querystring = require('querystring');
 
 process.on('uncaughtException', function (err) {
   debug.log("\n<<< UNCAUGHT EXCEPTION! >>>\n\n" + err);
@@ -121,7 +120,7 @@ var receive_server = http.createServer(function(request, response) {
     request.on('end', function () {
       ++messages_in;
 
-      var data = querystring.parse(body);
+      var data = JSON.parse(body);
       debug.log('notification: ' + JSON.stringify(data));
       broadcast(data);
       response.end();
@@ -140,7 +139,7 @@ var receive_server = http.createServer(function(request, response) {
         'messages.in': messages_in,
         'messages.out': messages_out,
         'log': config.log,
-        'version': 3
+        'version': 4
       };
 
       response.write(JSON.stringify(status));