Ticket 49235 - pbkdf2 by default
    
    Bug Description:  Now that we have improved the tuning somewhat
    we should offer a stronger default password hash. Wehave historically
    been poor at offering secure defaults, so this is a strong move
    to support this.
    
    Fix Description:  PBKDF2 by default. PBKDF2 helps to prevent
    certain classes of attacks by being resistant to bruetforce
    attacks due to the high work factor that an attacker must
    conduct to attempt to check the passwords content. Additionally
    the PBKDF2 impl we provide has a high random salt content (well
    in excess of current NIST requirements) which assits making
    bruteforces harder.
    
    https://pagure.io/389-ds-base/issue/49235
    
    Author: wibrown
    
    Review by: mreynolds (Thanks!)