[bug 989115] Implemented simple wiki landing page for configured locales

I implemented a decorator that requests certain configured locales to be redirected to a configured kb page. The settings still aren't set (waiting for the info) but the actual code is ready to go I think.

To test:
* Run tests
* Add 'es' to the 'SIMPLE_WIKI_LANGUAGES' setting. Go to '/es/products/firefox' and see it redirect you to '/es/kb/faq' which will be a 404 if you haven't created it.

r?