Support COUNT(0) as well as COUNT(1)

[tunetheweb]

L047 allows enforcing consistency of use of COUNT(*) or COUNT(1).

However some teams use COUNT(0) instead of either. Personally COUNT(1) has always made more sense to me, but that's by the by as sometimes you have to swallow your own preferences to follow team style.

So I would like to add the option to be able to enforce COUNT(0). I could see this being done in two ways:

• The easiest would be to add a prefer_count_0 flag similar to prefer_count_1, and then decide a precedence if both are set (I'd suggest prefer_count_1 for backwards compatibility).
• Perhaps a cleaner way (in terms of config anyway) would be to to change this to a prefer_count="1" option, that could also be set to "0", though that would be a breaking change (unless you supported both - in which case you might as well just go with the first option).

Any thoughts on this?

Happy to tackle this one myself btw.