Add dynamic DNS updates to FreeIPA
    
    This adds two new options:
    
    ipa_dyndns_update: Boolean value to select whether this client
    should automatically update its IP address in FreeIPA DNS.
    
    ipa_dyndns_iface: Choose an interface manually to use for
    updating dynamic DNS. Default is to use the interface associated
    with the LDAP connection to FreeIPA.
    
    This patch supports A and AAAA records. It relies on the presence
    of the nsupdate tool from the bind-utils package to perform the
    actual update step. The location of this utility is set at build
    time, but its availability is determined at runtime (so clients
    that do not require dynamic update capability do not need to meet
    this dependency).