Fix execution on PyPy (Fixes #19)
Python 3.3's ipaddress for Python 2.6 and 2.7.
Note that you must pass in unicode objects when constructing from a character representation!
Correct:
ipaddress.ip_address(u'1.2.3.4')
Wrong:
ipaddress.ip_address('1.2.3.4') ipaddress.ip_address(b'1.2.3.4')
