Link to the user summary from the user admin page
Add a dashboard portlet for searching users
Properly display transactions dealing with groups in role groups

The new transaction code assumed that the principals added and removed
from role groups were always users; properly handle the case where they
are groups instead.

RT 4.0 and earlier displayed them as "AdminCc GroupName added"; this
changes the wording slightly to add the word "group" before the group
name, to differentiate it from the cases where a user of that name was
added.
Merge branch '4.2/user-summary-from-admin'
Merge branch '4.2/find-user-portlet'
Merge branch '4.2/history-display-groups-in-roles'