closing bug #114837

* configure.in: Added checks for IPv6 support and getaddrinfo().

* acconfig.h: Defined HAVE_GETADDRINFO and SUPPORT_IP6.

* config.h.in: Defined HAVE_GETADDRINFO and SUPPORT_IP6.

* nanoftp.c: Structure xmlNanoFTPCtxt contains either sockaddr_storage
  field or sockaddr_in field, depending upon the availability of IPv6
  support.
  have_ipv6(): Added to check for run-time IPv6 support.
  (xmlNanoFTPScanURL), (xmlNanoFTPUpdateURL), (xmlNanoFTPScanProxy):
  Modified to parse a URI with IPv6 address given in [].
  (xmlNanoFTPConnect): Changed to use getaddrinfo for address
  resolution, if it is available on the system, as gethostbyname
  does not return IPv6 addresses on some platforms.
  (xmlNanoFTPGetConnection): Modified type of dataAddr variable to
  sockaddr_storage or sockaddr_in depending upon the IPv6 support.
  Sending EPSV, EPRT or PASV, PORT depending upon the type of address
  we are dealing with.

* nanohttp.c: ...