Start using the new JS Font Awesome kit

[lewisgoddard]

The new kits from Font Awesome include some neat accessibility features we should integrate.

• Use SVG instead of Webfonts
• Make sure "Auto-Accessibility" is turned on
• Make sure "Asynchronous Icons" is turned on
• Make sure "Include v4 Shim" is turned off
• Update kit code
• Add title to all non-decorative icons for accessibility

[lewisgoddard]

Assuming we can have multiple active kit codes with our pro subscription, could we get a code set up with these settings for testing? @btkostner