Add premessage-deflate extension handler for HTTP WebSocket.

Motivation:

- Need to handle premessage-deflate extension for HTTP WebSocket.

Modifications:

- Remove UTF8 checking of WebSocketFrames from frame decoder in order to
let pass compressed frames to the next handler.
- Add a WebsocketPremessageDeflateHandler to negociate ZLib windowSize
and initialize the frame deflater/inflater.