py-netaddr: updated to 0.8.0

Release: 0.8.0

* Fixed weak reference support in classes with ``__slots__``
* Added ``__bytes__`` to ``IPAddress`` for intuitive usage
* Added ``format()`` function to EUI
* Added ``IPNetwork.netmask`` property setter
* Added support for IABs in the ``40:D8:55`` OUI
* Drastically optimized ``spanning_cidr()``
* Fixed ``"x.x.x.x/x" in IPNetwork`` tests
* Added support for passing iterables of ``IPRange`` to ``IPSet`` and ``cidr_merge()``

Specific bug fixes addressed in this release
- N log N complexity instead of linear
- Efficiently creating a large IPSet from a list of IPRanges?
- Weak reference support

(adam)