Summary:
We currently have two relatively distinct applications, "People" and "Settings", living in /people/. Move settings to its own directory.
This renames a couple of classes but makes no real code changes.
Test Plan: Browsed /settings/, changed some settings.
Reviewers: btrahan, vrana
Reviewed By: btrahan
CC: aran
Maniphest Tasks: T1569, T631
Differential Revision: https://secure.phabricator.com/D3256
