Fix the What's New? phabricatorbot handler.
Summary: What's new has been broken for awhile, I've updated it to use the feed.query text view.
Test Plan: Start up a bot and say "What's new?"
Reviewers: epriestley, #blessed_reviewers
Reviewed By: epriestley
CC: fas, epriestley, aran, Kage, demo
Differential Revision: https://secure.phabricator.com/D8118