OAuth1.0 for single user access implementation complete

- The OAuth1.0 process for single user access (an instance where you
  already have in your posesssion your consumer key, consumer secret,
  acesss token, and access token secret) is complete.
- Note: The usage is subject to change. I'm not quite happy with how it
  all ties together just yet. I'd like to make it more transparent to
  the caller, and just cleaner in general.