Modernize Maniphest

Summary:
A few things
- pht Maniphest where I could
- implement dust background
- optimize pages for mobile
- adds aphront-two-column-layout
- reworks maniphest page with two column layout
- tweaks task table for mobile, though we should move to object-list-view

Stopping here as I want to get feedback in. Super excited about mobile and the new tasks views. Only sort of excited about the sidebar filters, they need more UI work, but we should talk about that.

Test Plan: Test Maniphest, Differential, and Homepage views. Sort tasks, make reports

Reviewers: epriestley, btrahan

Reviewed By: btrahan

CC: aran, Korvin

Differential Revision: https://secure.phabricator.com/D5314