Modularize all straightforward settings
Summary:
Ref T4103. This tackles all the easy stuff. Not yet handled:
- Translation, pronoun, timezone: these are weird and stored on the User object instead of in settings.
- Conpherence default: actually just missed this one, it's normal.
- 1000 dropdowns for email notification preferences (messy, technically).
Test Plan:
wow look at all these settings
Reviewers: chad
Reviewed By: chad
Maniphest Tasks: T4103
Differential Revision: https://secure.phabricator.com/D15999