The rationale for disabling this is: 1) systemd timers are better; 2)
it gets rid of one usually unnecessary process, which makes containers
more light-weight.
Note that cron is still enabled if services.cron.systemCronJobs is
non-empty, so this only matters if you have no declarative cron jobs
but do have user cron jobs.
Thanks to @domenkozar for implicitly reminding me that documentation is
probably our biggest issue. And I'm a dumbass for contributing to that
situation, so let's do better than that and document it.
The current changes are only preparation for a bigger change coming real
soon[TM] in Hydra and release-tools, so right now it's still a bit
tedious to create custom channels.
Signed-off-by: aszlig <aszlig@redmoonstudios.org>