Couple of Diffusion tweaks

Summary:

• Fix spacing on InfoView inside collasped boxes
• Fix spacing on stacked PropertyLists in TwoColumn
• Fix spacing on Readmes on Tablets
• Fix unset variable on importing commits

Test Plan: Review each of the above cases.

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin

Differential Revision: https://secure.phabricator.com/D15496