Rewrite WebSocket internals (#1410)

* Start rewriting Manager and Connection

* more stuff

* stuff

* Fix ready bug

* some stuff i forgot

* fix some stuff

* add stupid heartbeat ack like seriously who cares

* woo!

* fix a bug

* rate limit the dumb websocket

* stuff

* hdocs

* Docs

* Remove ClientManager#setupKeepAlive as it is now redundant

* Change Client._pingTimestamp to a getter that fetches the timestamp from the WebSocketConnection

* are you happy now eslint smh

* make gus happy

* Add CloseEvent external doc

* Make sure to emit 'reconnecting' when actually reconnecting

* ffs

* Fix RESUME logic

* Add heartbeat ack debug messages, including latency data

* Dumb stuff for Gus

* thx eslint

* more dumb stuff

* more dumb crap smh gus i h8 u

* moar messages

* fix for using wrong status, causing certain events not to be fired (#1422)

src/client/ClientDataManager.js

@@ -15,7 +15,7 @@ class ClientDataManager {
   }
 
   get pastReady() {
-    return this.client.ws.status === Constants.Status.READY;
+    return this.client.ws.connection.status === Constants.Status.READY;
   }
 
   newGuild(data) {