Log Message:
Update to 0.28.2.

 User-visible changes:
 * MAJOR BUGFIX:  revert revision 6764.

      The new history-searching code was over-stressing our use
      of BerkeleyDB transactions, causing checkouts to go
      twice as slow and lose all concurrent-client scalability.

      This is a temporary fix for a larger design problem.  See issue
      http://subversion.tigris.org/issues/show_bug.cgi?id=1499