R1:b3d7ed3e8e09

Respect users with duplicate real names in commit parser

Test Plan:
$parser->resolveUserPHID('Lei Zhao');
$parser->resolveUserPHID('Jakub Vrana');

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Korvin

Differential Revision: https://secure.phabricator.com/D3437