Replaces sudo with su in init script

resolves issue #800
http://stackoverflow.com/questions/8940771/switch-user-in-a-init-script
@spuder let's use start-stop-daemon? 

It should be available on centos if you have the right dependencies installed and is available on ubuntu as well.

Otherwise we are bikeshedding over cosmetics that we don't always fully grasp (speaking for myself)