Since the latest discussion about uploading .deb packages into official Debian repo I've decided to help a bit by fixing various errors and warnings. All the errors are fixed except for those related to start/stop scripts because I think the right course would be to drop them entirely and use systemd's .service files instead. The remaining warnings are either about lack of manpage or some debian-specific changelog version magic which I've failed to understand from reading its description - someone with better English skills should volunteer to fix both :)