Allow which services are started to be controlled.

This is so we can use the same api umbrella installer package but then
tailor different servers depending on their role (eg, separating the
database servers).
Change default HTTP ports to 80 and 443 and start as root.

In order to bind to these ports, we must start as a super user and then
we'll use supervisor to start the rest of the processes as less
privileged users.
Fix the number of header lines expected in the full stack.

Now that api-umbrella-gatekeeper doesn't pass the api-key to the backend
by default, the total number of headers has changed. See:
https://github.com/NREL/api-umbrella-gatekeeper/commit/4f762f212bc4100908110e3d403f8b3e39109390