Add more dual stack consideration.

Add more dual stack consideration.

    -Should retry as much as possible when some of source
     routing intermediate hosts' address families missmatch
     happened.
     (such as when a host has only A record, and another host
     has each of A and AAAA record.)

    -Should retry as much as possible when dest addr and
     source addr(specified with -s option) address family
     missmatch happend

Approved by: jkh