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/routes.js

@@ -0,0 +1,65 @@
+import IndexPage from './components/IndexPage';
+import DiscussionPage from './components/DiscussionPage';
+import PostsUserPage from './components/PostsUserPage';
+import DiscussionsUserPage from './components/DiscussionsUserPage';
+import SettingsPage from './components/SettingsPage';
+import NotificationsPage from './components/NotificationsPage';
+
+/**
+ * The `routes` initializer defines the forum app's routes.
+ *
+ * @param {App} app
+ */
+export default function(app) {
+  app.routes = {
+    'index': {path: '/all', component: IndexPage.component()},
+    'index.filter': {path: '/:filter', component: IndexPage.component()},
+
+    'discussion': {path: '/d/:id', component: DiscussionPage.component()},
+    'discussion.near': {path: '/d/:id/:near', component: DiscussionPage.component()},
+
+    'user': {path: '/u/:username', component: PostsUserPage.component()},
+    'user.posts': {path: '/u/:username', component: PostsUserPage.component()},
+    'user.discussions': {path: '/u/:username/discussions', component: DiscussionsUserPage.component()},
+
+    'settings': {path: '/settings', component: SettingsPage.component()},
+    'notifications': {path: '/notifications', component: NotificationsPage.component()}
+  };
+
+  /**
+   * Generate a URL to a discussion.
+   *
+   * @param {Discussion} discussion
+   * @param {Integer} [near]
+   * @return {String}
+   */
+  app.route.discussion = (discussion, near) => {
+    const slug = discussion.slug();
+    return app.route(near && near !== 1 ? 'discussion.near' : 'discussion', {
+      id: discussion.id() + (slug.trim() ? '-' + slug : ''),
+      near: near && near !== 1 ? near : undefined
+    });
+  };
+
+  /**
+   * Generate a URL to a post.
+   *
+   * @param {Post} post
+   * @return {String}
+   */
+  app.route.post = post => {
+    return app.route.discussion(post.discussion(), post.number());
+  };
+
+  /**
+   * Generate a URL to a user.
+   *
+   * @param {User} user
+   * @return {String}
+   */
+  app.route.user = user => {
+    return app.route('user', {
+      username: user.username()
+    });
+  };
+}