R1:add20783abb9

Restyle remarkup file links

Summary: Removes the icon image, uses font awesome. Better spacing.

Test Plan: Attach files to task, see new layout. click file, click download.

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin

Maniphest Tasks: T3612

Differential Revision: https://secure.phabricator.com/D16918