Improve Ponder on Mobile

Summary: Ponder was pretty unusable on mobile, I fixed most of the issues and ran some pht's as well.

Test Plan: Use Ponder //shudder//

Reviewers: epriestley, btrahan

Reviewed By: epriestley

CC: aran, Korvin

Differential Revision: https://secure.phabricator.com/D5977