Move to webpack

Signed-off-by: Julius Härtl <jus@bitgrid.net>

js/webpack.dev.config.js

@@ -0,0 +1,6 @@
+const merge = require('webpack-merge');
+const baseConfig = require('./webpack.config.js');
+
+module.exports = merge(baseConfig, {
+	devtool: 'eval'
+});