Substantively, this makes the table more readable by grouping users
into expanding sets by level of activity: active in last day, active
in last week, have an account at all. The class "active in last week",
as opposed to "active in last week but not in last day", makes more
natural comparisons both between realms and for one realm through time,
and it's less sensitive to the details of our definitions.
This also makes the terminology more standard. We already made that
change in the display, in the previous commit; as we go through the
logic here, we adjust the terminology in the code too.
This shows the number of messages sent by humans for the last
eight 24-hour periods, for each realm. "Messages sent" isn't a
perfect metric of activity, but it's easier to query with our
current data model than certain other statistics.
(imported from commit 9de3c479640a0b9dbc017b245dda21d951f4efa4)
Greg Price
Aditya Bansal
Rishi Gupta
Umair Khan
Steve Howell