Hovering over user names (and user circles for PM List) now displays
Name, Status Message and Last online time in a js tooltip.
Hovering over group names displays the names of all group members.
Unavailable users are shown as "Last active: Today".
Hovering on a user circle in the Buddy List results in a js tooltip
with Active/Idle/Offline/Unavailable for
green/orange/white/white-with-line.
Resolves#11607.
Vinit Singh