Support CORS

Signed-off-by: Manson Li <manson.li@matchstick.tv>
WebsocketServer cannot forward message to senders.

spelling mistake.

Signed-off-by: Manson Li <manson.li@matchstick.tv>
Support persistent application.

Passing a negative 'maxInactive' to indicates it's a persistent application.

Signed-off-by: Manson Li <manson.li@matchstick.tv>