Update Phortune UI elements

Summary:
Ref T2787. Update some of the UI elements used by Phortune. Mostly gets rid of the old blue headers.

Also adds some sweet art.

Test Plan: Poked aroudn Phortune.

Reviewers: btrahan, chad

Reviewed By: chad

Subscribers: epriestley

Maniphest Tasks: T2787

Differential Revision: https://secure.phabricator.com/D9915