Ticket #612 - improve dbgen rdn generation, output
    
    https://fedorahosted.org/389/ticket/612
    Reviewed by: nhosoi (Thanks!)
    Branch: master
    Fix Description:
    added ability to create rdn values as sequential numbers - output to stdout
    added the -b flag which not only specifies the beginning number but makes
    the RDN values increasing numbers with optional 0 padding (as used by ldclt)
    using -o - will output to stdout
    if not using verbose, will only print out ldif
    Platforms tested: RHEL6 x86_64
    Flag Day: no
    Doc impact: Yes