Removed most of absolute_import imports

Should be unneeded with Python 2.7 and up.
Added some unicode_literals along the way.

tests/urlpatterns_reverse/included_namespace_urls.py

@@ -1,5 +1,3 @@
-from __future__ import absolute_import
-
 from django.conf.urls import patterns, url, include
 
 from .namespace_urls import URLObject