Changed text proportions: 18px font, 29px line.

See http://pearsonified.com/typography/

Switched order of icons in header:
- From left to right, Github, Twitter, email, search, feed
- In full view, Github/Twitter closer to avatar, indicating identity
- In mobile view, Github/Twitter far aside to easily make out
- In full view, Feed to the right most, easier to make out
- In mobile view, feed is hidden but also less practical

Moved LESS stylesheet to _less directory.