Add a Picture Menu Item for Profiles

Summary: Just making profiles a little nicer, adds a big picture, easier mechanism for updating photos. Also larger profile pictures... need to re-thumb?

Test Plan:
View my profile, edit my picture, view a stranger, see profile. Check mobile, tablet, desktop. Check action menu on mobile.

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin

Differential Revision: https://secure.phabricator.com/D17295