Improve search result listing

Summary:
Make it prettier, paginate, add user pictures, show document types, clean some
stuff up a little. Plenty of room for improvement but this should make it a lot
more useful.

Test Plan:
Here's what the new one looks like:
https://secure.phabricator.com/file/view/PHID-FILE-edce2b83c2e3a121c2b7/

Reviewed By: jungejason
Reviewers: tomo, jungejason, aran, tuomaspelkonen, mroch
Commenters: tomo
CC: aran, tomo, jungejason, epriestley
Differential Revision: 545