Font Awesome changes

[ct-martin]

Font Awesome seems to be moving to requiring an accord to use their CDN, or requiring self-hosted. This site currently uses their CDN but does not have an account. It is unclear if they intend to keep supporting the free CDN without an account, and documentation is using the free CDN seems to be locked up as well.

The best solutions would be either:

1. Self-host Font Awesome
2. Use Fork Awesome, a fork of Font Awesome 4 (which also has icons for a lot of open source projects)

https://forkaweso.me/Fork-Awesome/

We could get a free account, but with the track record on things requiring accounts, it'd be easier not to and would block this issue.

There are only a handful of places where icons are used on the site, so this should be an easy fix.