largo_post_social_links() needs proper escaping

It's outputting user data without escaping:

```
$output .= sprintf(__('<span class="twitter"><a href="http://twitter.com/share" class="twitter-share-button" data-url="%1$s" data-text="%2$s" %3$s %4$s %5$s>Tweet</a></span>', 'largo'),
				get_permalink(),
				get_the_title(),
				$twitter_link,
				$twitter_related,
				$twitter_count
			);
```