Make phabot understand Txxx.

Summary:
Maniphest tasks can now be summarized by referencing their respective T<id> in irc.

Test Plan:
03:29:28 <@CodeBlock> T218
03:29:29 <@codeblock-phabot> T218: NYANCAT (Priority: Wishlist) - https://secure.phabricator.com/T218
03:30:14 <@CodeBlock> T58 asdf foo bar baz mcFoo T163
03:30:15 <@codeblock-phabot> T58: Allow AphrontFormView to render as a <div /> instead of a form (Priority: Wishlist) - https://secure.phabricator.com/T58
03:30:15 <@codeblock-phabot> T163: arc amend is slow (Priority: Needs Triage) - https://secure.phabricator.com/T163
...
03:28:23 <@CodeBlock> Oh. Hah, I'm testing against production Conduit. Ah well.
03:28:40 <@CodeBlock> I don't always test my code...but when I do, I do it in prod! :D

Reviewers:
epriestley

CC:

Differential Revision: 551