Put Disable/Admin flags on profiles

Summary: Ref T4065. Moves the "disable / enable" and "make / unmake administrator" actions to profiles.

Test Plan: Disabled and enabled users, and made and unmade administrators.

Reviewers: btrahan

Reviewed By: btrahan

Subscribers: epriestley

Maniphest Tasks: T4065

Differential Revision: https://secure.phabricator.com/D8666