Enhance mkdirs.sh to handle systemd configuration for installed services.
The Helix Installer installs systemd unit files, but the SDP does
not (though it has templates for them). Thus the systemd config
is only handled for the first instance on a given machine, and
manual configuration of systemd services is required when adding
additional instances. When this feature is implementt, this manual
step will be eliminated.
This change will need to be coordinated with the Helix Installer,
so when it installs versions of SDP after this is deployed, it
defers to SDP to do systemd configuration, that's currently
handled only by the Helix Installer.