News blog

I had some issues with this plugin in combination with Django 1.5.1 and Django-CMS 2.4.1. Thanks to your work (63fb4aaede...cad8f65b23) I was able to make the plugin run as part of a new project. However, since there were still some issues to solve, I had to make some more changes. Now I want to return the help: this PR solves the problems and additionally cleans the code up even more. 
Furthermore 11 out of 18 tests pass after fixing problems like the URL namespace issue:
```python
self.assertEquals(reverse('en:blog_archive_index'), '/test-page-1/')
```
vs.
```python
with translation.override('en'):
    self.assertEquals(reverse('blog_archive_index'), '/en/test-page-1/')
````
or the location of the out auth ``TEMPLATE_CONTEXT_PROCESSORS``