Item12596: Sync HistoryPlugin from release11

The Unit Tests are NOT in sync, because trunk renders anchors
differently.  The rest of the changes are just revision info and
copyrights.

git-svn-id: http://svn.foswiki.org/trunk/HistoryPlugin@16962 0b4bb1d4-4e5a-0410-9cc4-b2b747904278