Webpack (#1367)

* Replace gulp with webpack and npm scripts for JS compilation
* Set up Travis CI to commit compiled JS
* Restructure `js` directory; only one instance of npm, forum/admin are "submodules"
* Refactor JS initializers into Application subclasses
* Maintain partial compatibility API (importing from absolute paths) for extensions
* Remove minification responsibility from PHP asset compiler
* Restructure `less` directory

js/src/common/helpers/humanTime.js

@@ -0,0 +1,19 @@
+import humanTimeUtil from '../utils/humanTime';
+
+/**
+ * The `humanTime` helper displays a time in a human-friendly time-ago format
+ * (e.g. '12 days ago'), wrapped in a <time> tag with other information about
+ * the time.
+ *
+ * @param {Date} time
+ * @return {Object}
+ */
+export default function humanTime(time) {
+  const mo = moment(time);
+
+  const datetime = mo.format();
+  const full = mo.format('LLLL');
+  const ago = humanTimeUtil(time);
+
+  return <time pubdate datetime={datetime} title={full} data-humantime>{ago}</time>;
+}