Added SimpleChat implementation in Golang

# SimpleChat #

I've added a SimpleChat implementation in Golang. It behaves exactly as what's demonstrated during the workshop.

## How to run ##
You need a Go compiler, which can be found at [the Go homepage](http://golang.org).
To run, type the following:

    cd /path/to/simplechat
    go run *.go

## Description ##
By default, the server runs on `localhost:4000`. You can modify this in the source.

## What's missing ##
* The server needs to provide more convenience, e.g. specify the address and port on the command line
* The code needs some refactoring
* The page needs a little more beautification.