Management of RFC6749 errors

This pull request includes some fixes about management of rfc6749 errors:

- First, check duplicate parameters
- Missing parameter is invalid_request error according to rfc6749
- mismatching_redirect_uri, missing_redirect_uri,invalid_redirect_uri are not defined in rfc6749 or OAuth Extensions Error Registry
- Check if response_type is present with a valid value according to rfc6749, then check if client is authorized
This description is the same as for InvalidRequestError (non fatal). Should mention that this error is used for fatal errors related to missing or duplicate/mismatching parameters.