Site updates: Meta tags and CAPTCHA

We've added a metatags module to change the way that Facebook and search engines show links to the site. Previously FB would pull text from the latest post, which led to some non-sequiturs on posts. From now on FB links to the front page should appear as

It also appeared that the CAPTCHA was appearing on user logins. Since we only wanted the CAPTCHA to prevent bots from registering accounts, we have removed this.