To avoid aborts because of the python venv could not be updated by
killing all processes that uses the venv.
It will be done all times to prevent any error, because it could not be
reliably detected if the type installs or updates NetBox.
The wrapper service will "control" the services added from the
__netbox_* types to provide a general interface. This is more dynamic
than the alias approach used previously. Through this, it is possible
to handle multiple wsgi services for netbox - if this works ..
See as a reference:
http://alesnosek.com/blog/2016/12/04/controlling-a-multi-service-application-with-systemd/
Because someone *want* to use something other than just gunicorn, it was
extracted to a own type. Because gunicorn is a bit deep in the netbox
installation process, it's a bit harder to isolate it.
`__netbox_uwsgi` will come, too.