Ability to dsiplay time in last week / month / year

[AD-Wright]

Motivation
To allow to easily "auto-remove" single-join players or visitors. Also gives a feeling of the overall server activity level / who the main community members are.

Solution
This could be as simple as an option to count time each new week / month / year, (i.e. time spent on the server in the current month) or as complex as server time in a rolling 7-day / 30-day period. Placeholder API tags for these values would be nice to allow inclusion in the server tablist.