Fix duplicated frontend.css include 

If you check e.g. the subscribe page, you'll see frontend.css is loaded twice. It's loaded in the dispatcher and the templates. Also the frontend.css of the dispatcher doesn't include the version tag.

I think the nicest solution is to remove all frontend.css includes except the one from the dispatcher. And add a version tag to the frontend.css of the dispatcher. 

Cheers,
Jurian