Fixed the display issue for formerly active users that wore no longer showing once they closed all connections.
Also made other fixes like the negative others and improved performance.
It could still be improved but for now it should do.
i did this because I can't figure out how to *not* stack the lines
after the areas. furthermore, removing the limit is essential to have
a proper resolution in the display.
In some cases it can be useful to know the maximum value of any row of an
aggregate (for example, the maximum number of logins by a single user), without
graphing each row separately (because there are too many or the rows change).
This change allows that by setting the "only" parameter to "max" or "min".