Debian INIT and NGINX update

Nginx config
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Nginx config should have _client_max_body_size_ set to some reasonably high value, since 

Debian INIT
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Created Debian INIT script, which reads /etc/default/docker-registry, if it exists, otherwise uses some sane defaults to start gunicorn via start-stop-daemon. This INIT script supports being symlinked to from /etc/init.d, must be run as root (for log and pid file creation), and, by default, starts processes as owner of the repo (can be reconfigured via config file or by directly editing the script)