- Add the crond init script for s6
- Add the RUN_CROND configuration variable to setup crond
- Crond will not be run by default (hence the `down` file in the service directory)
- `start.sh` check if RUN_CROND = "true" || "1" and remove this file to tell s6 to run the initscript
- Resolves#2597
Jean-Philippe Roemer