R1:c58bd95842b2

Conduit user.query method

Summary: also includes a PhabricatorPeopleQuery object

Test Plan: queried for various combinations username, realname, id, phid, and email. verified correct results.

Reviewers: epriestley

Reviewed By: epriestley

CC: zeeg, aran, Koolvin

Maniphest Tasks: T1075

Differential Revision: https://secure.phabricator.com/D2416