This shell wrapper brings it in line with the rest of the `make
foo-shell` commands and puts you in a better location in the container.
It also makes running tests easier since it sets up the virtualenv and
puts you in the right place to type `make test`

This includes copying some docs and making it more straightforward
for docker-compose to control how we spin it up on devstacks.

Override gunicorn to run on the nginx port, this is similar to what
other IDAs do, which is to use runserver and bind to the nginx port.
XQueue has multiple services (consumer and gunicorn) so we'll leave
docker-run.sh for now and just change the port specificed in the
supervisor file.

Bring the mysql/rabbit hostnames to the devstack standard names.