anchor.diff:  that has to be initialized by passing it to COMPLETE-AUTHENTICATION.
   
   According to spec https://dev.twitter.com/docs/auth/pin-based-authorization"
  -  (initiate-redirect-authentication "oob"))
  +  (let ((data (pin-request-token)))
  +    (setf *oauth-token* (cdr (assoc :oauth-token data))
  +          *oauth-token-secret* (cdr (assoc :oauth-token-secret data)))
  +    (format NIL "~a?oauth_token=~a" *oauth/authorize* *oauth-token*)))
   
   (defun initiate-server-authentication ()
     "Initiate the authentication through the server mechanism.
  
positive.code:   (let ((data (request-token callback-url)))
      (setf *oauth-token* (cdr (assoc :oauth-token data))
            *oauth-token-secret* (cdr (assoc :oauth-token-secret data)))
      (format NIL "~a?oauth_token=~a" *oauth/authorize* *oauth-token*)))
  
  (defun initiate-pin-authentication ()
    "Initiate the authentication through the PIN mechanism.
  
negative.code: 
  (defun generate-nonce ()
    "Generate a NONCE to use for requests. Currently this simply uses a v4-UUID."
    (write-to-string (uuid:make-v4-uuid))
  
    (defun parse-boolean (value)
      (when (string= value "true") T)))
  
  (defun to-keyword (string)
    (intern (cl-ppcre:regex-replace-all "_" (string-upcase string) "-") "KEYWORD"))
  