GrizzlyServerFilter has a public constructor, but is not public, while WebSocketAddOn is public but has no public constructor

In Tyus version 2.2.1 (latest I believe) GrizzlyServerFilter has a public constructor, but is not public, while WebSocketAddOn is public but has no public constructor, so I've needed to copy GrizzlyServerFilter and create my own WebsocketAddOn, and this makes no sense. Are you afraid someone might extend one of these classes, from this open source project? You're actually enforcing that behavior. Please either make GrizzlyServerFilter a public class, or make the constructor in WebSocketAddOn public, but preferably *both*.

Shall I create a pull request?