[web] Restructure and fix builds.

web/apps/rpcexplorer/gulpfile.js

 /*
   Copyright 2016 The LUCI Authors. All rights reserved.
   Use of this source code is governed under the Apache License, Version 2.0
   that can be found in the LICENSE file.
 */
 
 'use strict';
 
 // Include Gulp & tools we'll use
 var gulp = require('gulp');
 var luci = require('../gulp-common.js');
 var path = require('path');
 
-luci.setup(gulp, {
-  dir: __dirname,
+luci.setup(gulp, __dirname, {
   includes: function(gulp, layout) {
     return gulp.src([
         path.join('inc', 'bower_components', 'bootstrap', 'dist', 'css',
                   'bootstrap.min.css'),
     ]).pipe(gulp.dest(layout.dist('inc/bower_components/bootstrap/dist/css')));
   },
 });