Please review (take 4): [389 Project] #46: setup-ds-admin.pl does not like ipv6 only hostnames

[Noriko Hosoi]

Thanks a lot to Mark Reynolds for sharing the failing test case with 
me!  This patch should fix his setup problem...

https://fedorahosted.org/389/ticket/46

https://fedorahosted.org/389/attachment/ticket/46/0001-Trac-Ticket-46-add...

  Fix description:
  1) When Socket6 is used, if the same FQDN appears twice in
     /etc/hosts (e.g., localhost.localdomain for 127.0.0.1 and
     ::1), the result from getaddrinfo was not correctly shifted.
  2) perl require takes package name. In the commit 850005499bd9-
     2c5b9b0027f944fcd33633c8db46, a tag ":addrinfo" was mistakenly
     passed and it was ignored.  This patch checks the version of
     Socket.  If it is greater than 2.000, getaddrinfo in the
     Socket module is used.  Otherwise, it falls back to Socket6.