With the `deluge` user specified in the unit files it ties it to
that user and makes it unavailable for re-use by systemd user instance.
Remove the user and group from the unit files and put them in a separate
`user.conf` file that should be installed as an override file e.g. for
deluged.service this would be placed as follows:
/etc/systemd/service/deluge.service.d/user.conf
Add the systemd files to the tarball for package maintainers.
Closes: #2034
Use markdown to aid readability.
Update the README and use it for the long_description in setup.py
Add detailed requirement information to the DEPENDS files.
