* Update FontAwesome to v5.0.6
* Adapt DiscussionListItem-count icon to match FontAwesome 5 syntax
* Change icon name to match FontAwesome 5.0.6 fas icon
* Add font type prefix parameter to icon helper
* Add Enable Icon Prefix to show icon in Extension Page
* Fix invalid icon behavior
* Change icon name to match FontAwesome 5.0.6 far icon
* Use iconPrefix property on component
* Use full icon class name
* Update icon helper docblock
* Full icon class syntax