pass the parameters array to the oauth/auth_native_traditional POST call

[afraazali]

The authNativeTraditional was expecting an array of params but it wasn't sent along in the post call to 'oauth/auth_native_traditional'.

[JorgeSivil]

Hello @afraazali, apart from this error, which I also fixed, I had to comment throwing of // throw new MissingArgumentException(array('access_token', 'client_id', 'client_secret'));

Because the library was setting these in the URL query parameters (not post fields) and Janrain was throwing error "Validation Failed: request failed because form action '/widget/traditional_signin' didn't match request url '/oauth/auth_native_traditional?client_id=XXX&client_secret=XXXX"

It might be a Janrain error because we are never setting form_action

[JorgeSivil]

@gedex could you merge please?