Pass additional express response properties as node-oauth2-server Response options

[steffansluis]

node-oauth2-server offers an options-parameter to its Response constructor. I think express-oauth-server should pass (some) of the properties of the express response object via the options parameter, so that they are available on the node-oauth2-server response.

The particular reason I am interested in this is because of the problem I mentioned here, but I think the general concept of passing (some) properties could make it possible for express-oauth-server to more seamlessly proxy the request and reponse by implementing some of the principles of express, such as the locals property on the express reponse.