Ticket #529 - dn normalization must handle multiple space characters in attributes
    
    Bug description: This is the second half of the fix for #529.
    The first half fixed the DN normalization which used to allow
    DNs where only the number of spaces are different.  Now it is
    rejucted as expected. But it breaks the backward compatibility.
    
    Fix description: The upgrade script 80upgradednformat.pl called
    from "setup-ds.pl -u" checks the duplicated DNs and rename them
    if necessary.
    
    For instance, if there are 2 DNs:
      cn=test user0,dc=example,dc=com (entryid: N)
      cn=test    user0,dc=example,dc=com (entryid: M)
    then the upgrade script/tool modifies the second one as follows:
      cn=test user0 M,dc=example,dc=com (entryid: M)
    and the original "cn: test    user0" is kept in the attribute.
    The modified result is reported in "setup-ds.pl -u" as follows:
      !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
      Duplicated DN(s) were found and renamed.
      !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
      Renamed entry IDs are listed in /var/lib/dirsrv/slapd-ID/ldif/userRoot_conflict.txt.
    Contents of the conflict.txt:
      prinary entry ID: duplicated entry IDs
      13:16 18
      14:17
    
    https://fedorahosted.org/389/ticket/529
    
    Reviewed and commentted by Rich and Mark (Thanks!!)