initial browser live reload support

Hey, I made a few changes and added support for live browser reload.

Made this because existing solutions had some issues I could not stand.

This is just an initial version, so please bare with me ... :)
I'm basically trying to find out if you're even interested to add a feature like this.
It's disabled by default.

I know adding "ws" as a dependency might be a bit overkill, so I made it at least optional.

It was originally supposed to be compatible with "LiveReload" and it's protocol-7, but when I found out how bad the browser extension was, [I wrote my own](https://github.com/jsen-/livereload-chromium). The protocol was kept, so it might be somehow compatible - not tested at all, I'm thinking about changing it anyway.
There are just two commits there so it's pretty much in early stages too.

Comments welcome.