Add a link directly to Browse in Diffusion

Summary: Getting to the straight browse view went away, this adds a link back. I'll look at more long term solution for getting to grep search.

Test Plan: Click on header, get take to browse view.

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin

Differential Revision: https://secure.phabricator.com/D18421