auto/manual init w/ single bundle, BYO root element 🎉 (#1173)

* ensure that application is only initialized once

* allow for single bundle init

* enable manual initialization via global flag

webpack.prod.js

@@ -8,7 +8,6 @@ const UglifyJsPlugin = require('uglifyjs-webpack-plugin');
 module.exports = merge.smart(require('./webpack.base.js'), {
   entry: {
     cms: './index',
-    init: './init',
   },
   output: {
     path: path.join(__dirname, 'dist'),