Webpack (#14)

See https://github.com/flarum/core/pull/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"
* Restructure `less` directory

extensions/flags/js/src/admin/index.js

@@ -0,0 +1,31 @@
+import { extend } from 'flarum/extend';
+import app from 'flarum/app';
+import PermissionGrid from 'flarum/components/PermissionGrid';
+
+import FlagsSettingsModal from './components/FlagsSettingsModal';
+
+app.initializers.add('flarum-flags', () => {
+  app.extensionSettings['flarum-flags'] = () => app.modal.show(new FlagsSettingsModal());
+
+  extend(PermissionGrid.prototype, 'moderateItems', items => {
+    items.add('viewFlags', {
+      icon: 'fas fa-flag',
+      label: app.translator.trans('flarum-flags.admin.permissions.view_flags_label'),
+      permission: 'discussion.viewFlags'
+    }, 65);
+  });
+
+  extend(PermissionGrid.prototype, 'replyItems', items => {
+    items.add('flagPosts', {
+      icon: 'fas fa-flag',
+      label: app.translator.trans('flarum-flags.admin.permissions.flag_posts_label'),
+      permission: 'discussion.flagPosts'
+    }, 70);
+  });
+});
+
+// Expose compat API
+import flagsCompat from './compat';
+import { compat } from '@flarum/core/admin';
+
+Object.assign(compat, flagsCompat);