Web bugs march7th

Main fix here is the display of long Groups lists in the web groups/users chooser. Also a minor template bug-fix.

To test Groups list #9935
 - Log in as a user with a large number of groups (E.g. root)
 - Test switching to other groups (and choosing users within these groups)
 - Check that ALL Groups and Users are accessible (especially the last group & user).
 - See that users in a small number of Groups see the "regular" (unchanged) display without scrollbars etc.

To test history_details paging #10499
 - Need to check that paging works in history view. Need a date with a lot of activity (haven't actually tested this myself - the bug-fix was coding only).