webpack: Add the option to output the bell character on error when watching

When I’m starting webpack like this

webpack --watch

it’s difficult to see when a compilation error happens after I save a file.

It would be very helpful to have a configuration option to output the bell character everytime an error happens.

process.stdout.write('\x07');

The OSX Terminal.app will automatically show a little notification in the dock when the app is in the background or minimized and you can configure it to play sound, too (I think it’s off by default.)

The behavior depends on your terminal emulator, of course, but iTerm 2 also supports this.

Having this option would help spotting errors much earlier, because I often find myself having the terminal window in the background. Especially when developing on a laptop with only one screen.