Conpherence - some widget and display stuff

Summary:
this was originally "just" adding the icons like I had bundled into D4790. It morphed a bit though and does a few things

 - adds the icons
 - cleans up widget CSS generally a bit so scrolling always works
 - phutil_tag -- probably was a bad idea but I wanted to play with it. I think its harder to not break conpherence when you land the branch now maybs. Still up for fixing it immediately post land though.

Test Plan: played with conphernece a bit. Used FF and Chrome to verify CSS was looking okay-ish.

Reviewers: epriestley, chad

Reviewed By: epriestley

CC: aran, Korvin

Maniphest Tasks: T2399

Differential Revision: https://secure.phabricator.com/D4814