Replace font-awesome with fork-awesome

This patch replaces font-awesome with its fork called fork-awesome.
Besides the fact that the newer versions of font-awesome can't be
shipped with distros like debian due to license issues, fork-awesome
also provides more FOSS related icons and builds on top of version 4.7.x
of font-awesome, which we used until this patch.

Signed-off-by: Sheogorath <sheogorath@shivering-isles.com>

package.json

@@ -41,7 +41,7 @@
     "express-session": "^1.14.2",
     "file-saver": "^1.3.3",
     "flowchart.js": "^1.6.4",
-    "font-awesome": "^4.7.0",
+    "fork-awesome": "^1.1.3",
     "formidable": "^1.0.17",
     "gist-embed": "~2.6.0",
     "graceful-fs": "^4.1.11",