Refector the user searching logic from the Autocompleter into RT::Users

This lets any other front-end user searching borrow the logic (and
Oracle-aware magic) already present in the autocompleter.
Convert Exclude to a list of ids rather than a comma separated list
Limit the excludes list by AND

Otherwise this code generates (id != 7 OR id != 9) which returns both 7
and 9.  In the Group membership page, this meant users who are already
members were returned in the user autocompleter.

A separate branch 4.0/autocomplete-exclude fixes this for Groups
Exclude Nobody and RT_System in SQL

Instead of skipping these in perl, push the restriction down into SQL
via RT::Users->SimpleSearch.
Provide a simple, publicly accessible, user search

The results are currently unlinked, as there is no non-admin page about
a user to link to.
Rename UserAutocompleteFields to UserSearchFields

Now the configuration option is used in two places, it is misleading to
call it by a name containing "Autocomplete."

Log loudly about rename, but also be nice and make it "just work."
Make user search "sticky"
Focus the search box by default when loading the User Search
Factor out the user searching widget
Add a User Summary page

Shows the user search again, followed by a list of portlets specified in
UserSummaryPortlets.  No user customization is available, just a simple
list of things to display.
Jump directly to a user if selected by autocomplete
Add an ExtraInfo User portlet

A thin wrapper around Elements/User/ExtraInfo, this uses the
UserSummaryExtraInfo config to control how much data you want on your
User Summary.  It seems natural that you might list 4 or 5 attributes in
More About Requestors and then list more here.
Add user portlets for Active and Inactive tickets

Controllable by the UserSummaryTicketListFormat, and displayed by
default on the User Summary.
Add a simple Create Ticket user portlet

Tickets thus created sets the user as the Requestor
Show Titles for ticket lists on the User Summary

While "More About Requestor" may wish a more concise format, headings
are of use for a full-page display.
Clarify what the queue dropdown contains by integrating it into the sentence
Merge branch '4.2/user-summary'