Ticket #529 - dn normalization must handle multiple space characters in attributes
    
    Bug Description: Commit 69ff83598d517bed84922b1c7dd67cab023b4d99
    had a flaw -- handling normdn in upgradedn_producer had a
    problem.  The string was passed to the Slapi_DN in the entry
    using slapi_sdn_init_dn_passin, while the string could be
    modified at other places.
    
    Fix Description: This patch manages the normdn string more
    carefully.
    
    https://fedorahosted.org/389/ticket/529
    
    Reviewed by Rich (Thank you!!)