Minor search ui updates

Summary: Wanted to clean this up a little to make Deedy's diff hopefully easier. Removes some unneeded CSS, and Deedy's should remove more with object list.

Test Plan: Search for people, documents, tasks, etc. Test mobile and desktop layouts

Reviewers: epriestley, DeedyDas

Reviewed By: epriestley

CC: aran, Korvin

Differential Revision: https://secure.phabricator.com/D5880
Merge branch 'master' of github.com:facebook/phabricator