Fix Entry.get_absolute_url when USE_TZ is set to False #233

Conflicts:
	zinnia/models_bases/entry.py
	zinnia/tests/__init__.py
Fix breadcrumbs for Entry detail page with naive datetime #233
Fix EntryQuerysetArchiveTodayTemplateResponseMixin when USE_TZ is False #233
Fix EntryToday view when USE_TZ is set to False #233
Complete the tests of view with USE_TZ alternatively set to True and False, closes #233

Conflicts:
	zinnia/tests/views.py