R1:b348aaefb97a

Add Hovercards / restyle feed one line stories.

Summary: This adds hovercards to most stories and removes the profile photo from one line stories. I don't know about my implementation, which has difficulties with application transactions (because it shows status). Which leads me to a bigger question, which is can we render all people through a common function like AphrontTagView so we can easily class and/or hovercard it anywhere.

Test Plan: Reviewed my feed, various stories.

Reviewers: epriestley…