Trac Ticket #338 - letters in object's cn get converted to
       lowercase when renaming object
    
    Fix description: In modrdn, if newrdn is different from the oldrdn
    only by upper/lower cases, it was ignored in the entryrdn code.
    This patch recognizes the change and updates the entryrdn index.
    commit b1ed11117e02c0ae670f05f9850b20fd9334d567
    (cherry picked from commit 197a8f5c6a4def3915cd07d07602e3ed80b082b0)