Linking the unixname in Phabricator's blame view to the employee's profile.

Test Plan:
Visit page
http://phabricator.devXXXX.snc6.facebook.com/diffusion/E/browse/tfb/trunk/www/hphp_files.mk?view=blame
and verify that unixnames are hyperlinks leading to emplyees' profiles.

Task: T297

Reviewed By: tuomaspelkonen
Reviewers: tuomaspelkonen, epriestley
Commenters: epriestley
CC: aran, blazej0, epriestley, tuomaspelkonen
Differential Revision: 622