Upgraded Font Awesome, and made necessary fixes.

The previous version of Font Awesome included in the theme gave errors with the local simple Pelican server. Upgrading to 4.0.3 (which is made for Bootstrap3) fixed the error, but requires changes because the icon names have changed.

This fixes #18 (as far as I can tell).
Merge pull request #19 from hlapp/fix-fontawesome

Upgraded Font Awesome, and made necessary fixes.