Massive JavaScript cleanup

- Use JSX for templates
- Docblock/comment everything
- Mostly passes ESLint (still some work to do)
- Lots of renaming, refactoring, etc.

CSS hasn't been updated yet.

js/lib/helpers/icon.js

@@ -1,3 +1,12 @@
-export default function icon(icon) {
-  return m('i.fa.fa-fw.fa-'+icon)
+/**
+ * The `icon` helper displays a FontAwesome icon. The fa-fw class is applied.
+ *
+ * @param {String} name The name of the icon class, without the `fa-` prefix.
+ * @param {Object} attrs Any other attributes to apply.
+ * @return {Object}
+ */
+export default function icon(name, attrs = {}) {
+  attrs.className = 'icon fa fa-fw fa-' + name + ' ' + (attrs.className || '');
+
+  return <i {...attrs}/>;
 }