Ubuntu_etc_init.d

I added an optional time.sleep(20) to make it work during system boot using the provided /etc/init.d/cloudprint for ubuntu under a user named cloudprint.  The wait is controlled by the new command-line option -w.

I also added system install instructions to the README to create the user and to start cloudprint during boot.

I believe the problem was that, although the network had started, some resource was not yet available e.g. perhaps resolv.conf was not yet populated with DNS IPs from DHCP; I don't like this approach (a hard-coded timer) but it does work on my laptop and on a clean system using http://instantserver.io/.  

I think for --chuid and --group you want to replace $CPNAME with $CPUSER.