Encode strings into the packfile side-band format that git uses. Useful for sending messages to clients doing git push so that your messages show up in their stdout.
Used in https://github.com/substack/git-http-backend
Inspired by @dz0ny from https://github.com/substack/pushover/pull/10, rewritten by me
var encode = require('git-side-band-message')
var msg = encode('hello there!')
gitCloneResponseStream.write(msg)