Add permessage-deflate and deflate-frame WebSocket extension
implementations.
Motivation:
Need to compress HTTP WebSocket frames payload.
Modifications:
- Move UTF8 checking of WebSocketFrames from frame decoder to and
external handler.
- Change ZlibCodecFactory in order to use ZLib implentation instead of
JDK if windowSize or memLevel is different from the default one.
- Add WebSocketServerExtensionHandler and
WebSocketClientExtensionHandler to handle WebSocket Extension headers.
- Add DeflateFrame and PermessageDeflate extension implementations.