FSE-193: Add the option for where log info is sent for process. 

You can either write them to the standard /var/log file using `file` or print them to STDOUT using `stdout`. You can set which one you want using a node attribute (the same way you set the runit commnad). 

To handle this I created two classes: Log::Reader and Log::Writer that will handle the transport of log lines from runit to chef-init and finally to STDOUT.