Authentication as a middleware

[tracend]

Building the authentication for the library has become a body of its own.

As it is gearing out of the core scope for the library, and keeping node principals that are specialised in one thing, it is reasonable to suggest that the oauth server needs to be externalised as a separate module.

On the downside, the lib will come with no authentication process by default - but it can look out for middleware that will handle authentication during the connect() request....