Quicksand - update title while navigating about

Summary: Fixes T7744. Also fixes a bug where we were copying the response object erroneously; that's not necessary to move around since we cleanly initialize it for each load

Test Plan: from user profile, clicked feed tab and saw new title. clicked calendar tab and saw new title. clicked back and saw feed title and page render.

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin, epriestley

Maniphest Tasks: T7744

Differential Revision: https://secure.phabricator.com/D12487