Port a few various options.

Summary:
- remarkup.enable-embedded-youtube
- controller.oauth-registration
- aphront.default-application-configuration-class
- cache.enable-deflate

Test Plan: Saw the new options in the web interface.

Reviewers: epriestley, chad, btrahan

Reviewed By: epriestley

CC: aran, Korvin

Maniphest Tasks: T2255

Differential Revision: https://secure.phabricator.com/D4424