R1:72119e786c79

Convert "bool" config values to new modular system

Summary: Ref T12845. Moves the "bool" values over.

Test Plan: Set, deleted, and mangled bool values from CLI and web UI.

Reviewers: chad, amckinley

Reviewed By: amckinley

Maniphest Tasks: T12845

Differential Revision: https://secure.phabricator.com/D18158