R1:23487dc35768

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