Alaveteli Theme Upgrade

This is to resolve #310. Thanks to @henare for getting me setup with an environment in which to test this.

Tested so far:
- Home Page (Done by removing lib/views/general/_frontpage_bodies_list.html.erb and lib/views/general/_frontpage_requests_list.html.erb and having Alaveteli serve these up)
- Making Requests
- Replying to requests from within RTK
- Help Pages

Currently Broken:
- Blog (I think this has more to do with SSL Certs then with RTK)
- Stats (This issue an issue with the foi-live-creation.jpg and foi-user-use.png not being created it would seem, and I'm not too sure how that all works)/

Testing was completed with vagrant compiled using the instructions at https://github.com/mysociety/alaveteli/blob/rails-3-develop/Vagrantfile

Can someone perhaps review this and let me know if any changes are needed?