Added Httpd class and API config options.

src/config.json

@@ -22,5 +22,10 @@
             "keepalive": true,
             "nicehash": false
         }
-    ]
+    ],
+    "api": {
+        "port": 0,
+        "access-token": null,
+        "worker-id": null
+    }
 }