[Feature] Add websocket interface

[dougdellolio]

for https://github.com/kerryjiang/WebSocket4Net/issues/130. ran across the same thing in my own project. I think this is all this needs. let me know if I am missing something.

[kerryjiang]

I will add it in master branch

[kerryjiang]

Thanks, I added it in the master branch. https://github.com/kerryjiang/WebSocket4Net/commit/8bbb61b65bdb148020313c8ba44eb1b9e90ec800