[arch-general] Change Arch's default crond

[Thomas S Hatch]

I can think of three considerations for a cron daemon:
1 . Minimal - its a cron daemon, it does not need to be complex
2. Active development
3. Anacron functionality

As far as I can see this leaves us with fcron, dcron and cronie. Cronie
probably has the highest assurance for upstream development because it is
backed by redhat.
But I think that having a cron daemon as default that has issues executing
jobs on time and as they are defined is highly questionable.