How To: Update font awesome fonts from version 3 to 4

With the merging of https://github.com/Shopify/dashing/pull/687, some community widgets may have issues rendering icons if they used Font Awesome. If you find a missing icon, you can most likely update it following this guide: https://github.com/FortAwesome/Font-Awesome/wiki/Upgrading-from-3.2.1-to-4