Update Harbormaster for two column

Summary: Updates the Harbormaster UI to match the new two column everywhere else.

Test Plan: Did best I could, tested builds, plans, steps, buildables. Unable to test lint/unit locally, I need to set that up. Kick the tires for me pls. :3

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin

Differential Revision: https://secure.phabricator.com/D15523