Gns3-netifaces

All changes in this version relate to the ioctl( ) code path,
which is not used on Windows or on any modern UNIX or UNIX-like
system that implements getaddrinfo().

* Fixed bit-rot in the ioctl() code path.
* Fixed a problem with setup.py that might manifest itself if the
config.cache file was manually edited.
* Fixed the ioctl() code path to cope with systems that have
sa_len and return longer than normal struct ifreq requests from
SIOCG[L]IFCONF (for instance, Mac OS X).

* Dropped support for Win2K and earlier
* Added support for addresses other than IPv4 on Windows
* Removed empty 'addr' entries for interfaces that don't provide
any addresses.
* Fixed problems with setup script that prevented it running on
Windows, and improved the chances of it working with
cross-compilers somewhat.
* Added a verion property to the module that you can test at
runtime.

* Added a workaround for a FreeBSD kernel bug (kern/152036).
* Added address_families dictionary to allow code to look up the
symbolic name corresponding to a given numberic address family
code.