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/forum/components/EventPost.js

@@ -0,0 +1,80 @@
+import Post from './Post';
+import { ucfirst } from '../../common/utils/string';
+import usernameHelper from '../../common/helpers/username';
+import icon from '../../common/helpers/icon';
+
+/**
+ * The `EventPost` component displays a post which indicating a discussion
+ * event, like a discussion being renamed or stickied. Subclasses must implement
+ * the `icon` and `description` methods.
+ *
+ * ### Props
+ *
+ * - All of the props for `Post`
+ *
+ * @abstract
+ */
+export default class EventPost extends Post {
+  attrs() {
+    const attrs = super.attrs();
+
+    attrs.className += ' EventPost ' + ucfirst(this.props.post.contentType()) + 'Post';
+
+    return attrs;
+  }
+
+  content() {
+    const user = this.props.post.user();
+    const username = usernameHelper(user);
+    const data = Object.assign(this.descriptionData(), {
+      user,
+      username: user
+        ? <a className="EventPost-user" href={app.route.user(user)} config={m.route}>{username}</a>
+        : username
+    });
+
+    return super.content().concat([
+      icon(this.icon(), {className: 'EventPost-icon'}),
+      <div class="EventPost-info">
+        {this.description(data)}
+      </div>
+    ]);
+  }
+
+  /**
+   * Get the name of the event icon.
+   *
+   * @return {String}
+   */
+  icon() {
+    return '';
+  }
+
+  /**
+   * Get the description text for the event.
+   *
+   * @param {Object} data
+   * @return {String|Object} The description to render in the DOM
+   */
+  description(data) {
+    return app.translator.transChoice(this.descriptionKey(), data.count, data);
+  }
+
+  /**
+   * Get the translation key for the description of the event.
+   *
+   * @return {String}
+   */
+  descriptionKey() {
+    return '';
+  }
+
+  /**
+   * Get the translation data for the description of the event.
+   *
+   * @return {Object}
+   */
+  descriptionData() {
+    return {};
+  }
+}