Add python 3.3 to python and allow_failures #148
remove dependency on unittest2

This allows support for both python 2.6 and 3.3
use @willkg 's implementation of skip_if
only test python 3.3 with DJANGO_VERSION=1.5
setup.py: in version checking code use utf8 encoding
use django-nose version that supports Python 3
fix lack of basestring in python 3 using six
use newer urllib.parse on python3
use reload_module from six instead of reload
use six.text_type.encode to test for non-ascii bytes_type
convert emails to utf-8 bytes before hashing, if they are unicode

This could result in some issues, eg the behavior of default_username_algo  will change subtly from py2 to py3k