Added Foundation Icons v3

Source: http://zurb.com/playground/foundation-icon-fonts-3 and
http://zurb.com/playground/uploads/upload/upload/288/foundation-icons.zi
p

CSS min’d, removed preview.html - other files as-is. Updated homepage
and keywords in package.json to bring up-to-date.

Second attempt. Supercedes #2287 and #2288.