Tests: Fixed widget html output tests for Django 1.4, now uses assertHTMLEqual
Apparently Django 1.4 widgets html output is different by attribute order
Therefor refactored tests so it uses assertHTMLEqual instead of assertEqual
Removed dependecy from django.utils.six (django 1.4.2)
Otherwise support for 1.4.0 is broken
As we have plans to support some popular packages (like Django-CMS)
we can't use this library, because some of them still requires 1.4.0