Adds font awesome. Replaces icons in 'follow us' and footer with FA icons.
Adjusts blog h3 spacing
Cleans previous and next post styles. Makes entire area clickable as well (request as per user feedback).
Adds related links code and styles.
Moves 'back to blog' link. Adds space on top of bare template to compensate for usa bug.
Cleans follow us links at the bottom of blog posts
Merge pull request #437 from 18F/feature/clean-blog-layout

Feature/clean blog layout