Add reverse DNS record when forward is created
    
    Adding reverse DNS record may be a time consuming task, especially
    for IPv6 addresses. Having a way to automatically create a reverse
    record when a forward record is created could speed up the process.
    host-add command already has this possibility.
    
    This patch takes advantage of the new per-type API and adds new
    options for A/AAAA record types: --a-create-reverse and
    --aaaa-create-reverse. These commands can be used to automatically
    create reverse records for new A/AAAA addresses (both forward
    and reverse zones need to be managed by FreeIPA server):
    
    ipa dnsrecord-add example.com foo --a-rec=10.0.0.1 --a-create-reverse
    
    This command would add a new A record to record foo in zone
    example.com and a PTR record to appropriate reverse zone for
    IP address 10.0.0.1 (for example PTR record 1 in zone
    0.0.10.in-addr.arpa. pointing to foo.example.com.).
    
    Few modification were done to new DNS API to support this feature:
     - Refactor --ip-address option handling from host-add and place it
       to dns.py to be used by both modules
     - Add support for "extra" per-type options
     - Hide DNS record part options in dnsrecord_find command as they
       have no effect for this command
    
    https://fedorahosted.org/freeipa/ticket/2009