Initial commit of the OAuth Connector module. A module for easily enable users to sign in through OAuth enabled API:s.

Passes around the connector definition a bit more to make it easier for one connector module to provide multiple connectors.

Made it possible to specify a realm as well as to send parameters when using the oauth authentication header.

Added support for authentication realms and POST-requests in token exchanges. Made POST-requests the default as suggeste din the OAuth standard.

Not always is the name of the user to be found on the same resource as the unique id. Made it possible to fetch two resources.