Uff solved:

(...)
       my $chang = &_changes($entry->get_value("changes"));
       my %changes = %$chang;

sub _changes {
        my $changesSTR = shift;
        my (%changes, @tmp);
        $changesSTR =~ s/\n/ /g;
        foreach my $element(split(/\s-\s/,$changesSTR)){
            if ($element =~ m/(replace|add|delete):\s+([^\s]*)\s*\w+\s
+*:\s*(.*)$/) {
                  my ($var1,$var2,$var3) = ($1, $2 ,$3);
                  push @tmp,$var3 ;
                  $changes{$var1}{$var2} .= "@tmp" ;
                  @tmp=undef;
             } elsif ($element =~ m/(replace|add|delete):\s+([^\s]*)$/
+){
                 $changes{$1}{$2} .= "undef" ;
             }
        }

        return \%changes;
}
[download]

Maybe solution is not pretty, but works ;)