Make it possible to have no --config-file= argument for the daemon.
  * Adds a RuntimeDirectory=/var/run/${PROJECT_NAME} in the systemd template,
    so that /var/run/${PROJECT_NAME} can be created on boot (Closes: #767711).
Using /run and not /var/run.
Using RuntimeDirectory=${PROJECT_NAME} as per advice in #debian-systemd.
Fix for bug #770706