Make the Aphlict server more resilient.

Summary:
Currently, the Aphlict server will crash if invalid JSON data is `POST`ed to it. I have fixed this to, instead, return a 400. Also made some minor formatting changes.

Ref T4324. Ref T5284. Also, modify the data structure that is passed around (i.e. `POST`ed to the Aphlict server and broadcast to the Aphlict clients) to include the subscribers. Initially, I figured that we shouldn't expose this information to the clients... however, it is necessary for T4324 that the `AphlictMaster` is able to route a notification to the appropriate clients.

Test Plan:
Making the following `curl` request: `curl --data "{" http://localhost:22281/`.

**Before**
```
sudo ./bin/aphlict debug
Starting Aphlict server in foreground...
Launching server:

    $ 'nodejs' '/usr/src/phabricator/src/applications/aphlict/management/../../../../support/aphlict/server/aphlict_server.js' --port='22280' --admin='22281' --host='localhost' --user='aphlict'

[Wed Jun 11 2014 17:07:51 GMT+0000 (UTC)] Started Server (PID 2033)
[Wed Jun 11 2014 17:07:55 GMT+0000 (UTC)]
<<< UNCAUGHT EXCEPTION! >>>

SyntaxError: Unexpected end of input
>>> Server exited!
```

**After**
(No output... the bad JSON is caught and a 400 is returned)

Reviewers: #blessed_reviewers, epriestley

Reviewed By: #blessed_reviewers, epriestley

Subscribers: epriestley, Korvin

Maniphest Tasks: T4324, T5284

Differential Revision: https://secure.phabricator.com/D9480

support/aphlict/server/lib/AphlictLog.js

@@ -4,16 +4,16 @@ var fs = require('fs');
 var util = require('util');
 
 JX.install('AphlictLog', {
-  construct : function() {
+  construct: function() {
     this._writeToLogs = [];
     this._writeToConsoles = [];
   },
 
-  members : {
-    _writeToConsoles : null,
-    _writeToLogs : null,
+  members: {
+    _writeToConsoles: null,
+    _writeToLogs: null,
 
-    addLogfile : function(path) {
+    addLogfile: function(path) {
       var options = {
         flags: 'a',
         encoding: 'utf8',
@@ -27,12 +27,12 @@ JX.install('AphlictLog', {
       return this;
     },
 
-    addConsole : function(console) {
+    addConsole: function(console) {
       this._writeToConsoles.push(console);
       return this;
     },
 
-    log : function(pattern) {
+    log: function(pattern) {
       var str = util.format.apply(null, arguments);
       var date = new Date().toLocaleString();
       str = '[' + date + '] ' + str;