MaxSampleCount/Age defaults need to be reconsidered and be configurable

I recently discovered that for statistics that can have a series of samples over time the default number of samples is 20, not sure what the default age is. I do not see where either value can be configured other than thru command channel commands. We should at provide configuration global configuration parameters for them, possibly allow them per statistic.

It would not surprise me if the having a default of 1 value per stat is what most users actually want.