Average Daily Traffic Metrics for Breakdown reports

[#1]

Would be really useful to be able to have "average daily traffic" in SiteCatalyst breakdown reports. This would let you see

- Average visits to a page per day

- Average daily visitors per country/platform

- Average number of Events that happen in a day.

As these are often the sort of stats that business users are after rather than aggregates of *all* events that happen in a period of time

(Potentally, it might be easier to just have a concept of "report period" so that you could use it in Calculated Metrics - ie, {daily page views} = {page views} / {reporting period}