Wrap the feed text rendering stuff with htmlspecialchars_decode
Summary: I've only seen this be an issue with PhabricatorBot.
Test Plan: Comment on something with characters that are automatically converted like "<>", and see what the irc bot reports
Reviewers: epriestley, Blessed Reviewers
Reviewed By: epriestley
CC: epriestley, aran
Differential Revision: https://secure.phabricator.com/D8140