Update .arclint in Phabricator for phutil-library lint

Summary:
Also fix a few other minor issues:

  - Use lint config.
  - Fix a method signature from `arc unit --everything` (unrelated).
  - Add a javelin doc.

Test Plan: Ran `arc lint`, `arc unit`, `arc linters`.

Reviewers: btrahan, joshuaspence

Reviewed By: joshuaspence

Subscribers: epriestley

Differential Revision: https://secure.phabricator.com/D9072