R1:7d771b4ff798

Support "M" in phid.lookup and ircbot

Summary: Fixes T2651. This could be futher generalized but it's a bit out of the way.

Test Plan: See chatlog.

Reviewers: chad

Reviewed By: chad

CC: aran

Maniphest Tasks: T2651

Differential Revision: https://secure.phabricator.com/D5236