Add an edit link on hover for Project profile images

Summary: Minor point of polish, but feels really nice. Hover over photo and edit a link to change the picture.

Test Plan:
hover hover, clicky clicky

{F1069179}

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin

Differential Revision: https://secure.phabricator.com/D15109