[webpack-focus] Default config should use DEV_MODE to initialize the OUTPUT_PUBLIC_PATH variable.

[durandx]

The following line is not a good idea : https://github.com/KleeGroup/webpack-focus/blob/master/webpack.config.js#L37

OUTPUT_PUBLIC_PATH = OUTPUT_PUBLIC_PATH !== undefined ? OUTPUT_PUBLIC_PATH : `http://${DEV_SERVER_HOST}:${DEV_SERVER_PORT}/`;

In the current form we need to set OUTPUT_PUBLIC_PATH to './' in "release mode" to prevent the loader from using localhost:3000/myfont.eot provided by webpack-dev-server

I think you should use the DEV variable to switch between DEV_SERVER_HOST or OUTPUT_PUBLIC_PATH. And you should also initialize OUTPUT_PUBLIC_PATH by default to './' like PACKAGE_JSON_PATH