Aggregator functions for Date Range(s)

[#1]

The only aggregation of any metric that is currently available for a selection of date range is SUM. Sometimes a user would want other aggregator functions like  AVERAGE, MAXIMUM, MINIMUM for that period. Users should be allowed to select the aggregator function they want, in either in the calendar selection menu or in add metrics popup.

[#2]

If we could use a calculated metric based on date ranges to achieve a % change metric, then we could also see the fastest rising and fastest declining products (ie Number of orders yesterday compared to last month), which would be very helpful.