[#705,theme][s]: switch all navbar links and footer links as per #705.
[#705,home][s]: inline front page content rather than using content proxy, tweak and remove sidebar.
[#705,refactor][s]: remove content (proxy) controller and all remaining references from code.
Put right sidebar back in
We won't remove it until when we do the frontpage redesign
Merge pull request #715 from openspending/705-front-page-links

Fixes #705 - front page links and layout (plus no longer need content proxy).