Remove `@group` annotations

Summary: I'm pretty sure that `@group` annotations are useless now... see D9855. Also fixed various other minor issues.

Test Plan: Eye-ball it.

Reviewers: #blessed_reviewers, epriestley, chad

Reviewed By: #blessed_reviewers, epriestley

Subscribers: epriestley, Korvin, hach-que

Differential Revision: https://secure.phabricator.com/D9859