R1:c3281c875747

Add conduit feed.query method

Summary: This is not totally done yet, and i'm submitting for feedback.

Test Plan: Played with various settings in local conduit console.

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, epriestley

Maniphest Tasks: T790

Differential Revision: https://secure.phabricator.com/D1555