Various bug fixes and small additions

IMPORTANT:
This commit contains new config options.
Make sure your local config file is up to date with config.example.toml to avoid issues.

CHANGELOG:
- Fix crash exploit caused by abnormally long WebSocket messages
- Added config option for limiting the maximum amount of active connections from the same IP
- Made per-IP turn limiter configurable
- Fixed an issue where vote updates were not sent to clients in some cases
- Added warning about using qmpSockDir on Windows hosts
- Updated dependencies
- Removed unused code/imports

src/RateLimiter.ts

@@ -5,7 +5,7 @@ export default class RateLimiter extends EventEmitter {
     private limit : number;
     private interval : number;
     private requestCount : number;
-    private limiter? : NodeJS.Timer;
+    private limiter? : NodeJS.Timeout;
     private limiterSet : boolean;
     constructor(limit : number, interval : number) {
         super();