Pull request for updated Social Hashtags

Hi shanaver, 

I and some of my team have fixed the Twitter OAuth authentication, and made some improvements to Social Hashtags. The changes are detailed in the README file. It would be great if you pulled these changes in so they are incorporated into the main branch that is distributed through WP.

Also, this is my first Pull Request in Github, so please feel to direct me if I am doing it wrong, or the information I am providing is incomplete. 

You can see a live version of this version of the plugin here: http://www.artspracticum.org/social/ -- there is a whitelist on that one, so you won't be able to post. 

Thanks,

Michael Mandiberg