Don't HTML escape entities identified by twitter-text-js, such as links

This will avoid the insertion of &amp;s in both the link text and the link's href generated but twitter.autoLink()

You can see some of my experimentation with this at http://requirebin.com/?gist=4f0fe3994b1e9d100aa6, I believe this will still prevent a user from injecting HTML, the entity identification seems very strict.