include sample link url, post
include link posts in post index, with external url, timestamp
Include Disqus script only if shortname is present in _config.yml
Merge pull request #43 from maxheld83/link-post

Link posts / Linklog (john gruber style, similar to hpstr)
Add icon to link post heading in indexes
Merge branch 'link-post-design' into gh-pages
Add sample link post