Remove @group annotations
Summary: I'm pretty sure that @group annotations are useless now... I believe that they were originally used by Diviner?
Test Plan: Eye-balled it.
Reviewers: epriestley, Blessed Reviewers
Reviewed By: epriestley, Blessed Reviewers
Subscribers: epriestley, Korvin, aurelijus
Differential Revision: https://secure.phabricator.com/D9855