R1:a57f5d1562b6

fixed overlong differential feed story titles

Summary:
Previously, the comment and/or summary would be added to the title. This
is incorrect behavior.

Test Plan: observed change

Reviewers: epriestley

Reviewed By: epriestley

CC: allenjohnashton, keebuhm, aran, Korvin

Differential Revision: https://secure.phabricator.com/D2701