Aditional data to $auth.authenticate

Made possible that the $auth.authenticate function can receive a second parameter (Object) that will be passed all the way down the oauth request pipeline (either OAuth1 or OAuth2) to be sent the the server's final post.
ex. In a Facebook login, after the popup has closed, it will be object will be serialized along with the code, clientId and redirectUri and sent to the server

This is my first pull request in a long time, so I'm not really sure if I did everything correctly, or organized, but the code is working. I don't know how to write unit tests for JS, as I told in issue #114, I haven't properly tested with OAuth 1.0, but it should work just fine.
I think my text editor kept your indentation correctly.