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/util/Constants.js

@@ -70,6 +70,13 @@ exports.DefaultOptions = {
   },
 };
 
+exports.WSCodes = {
+  1000: 'Connection gracefully closed',
+  4004: 'Tried to identify with an invalid token',
+  4010: 'Sharding data provided was invalid',
+  4011: 'Shard would be on too many guilds if connected',
+};
+
 exports.Errors = {
   NO_TOKEN: 'Request to use token, but token was unavailable to the client.',
   NO_BOT_ACCOUNT: 'Only bot accounts are able to make use of this feature.',