Give custom controls passable disabled states
Summary: Fixes T9871. Ref T10004. These won't win any awards but it fixes them being incredibly weird and confusing.
Test Plan:
- Tried to use controls, got reasonable behavior.
- Used normal controls to make sure I didn't break anything.
Reviewers: chad
Reviewed By: chad
Maniphest Tasks: T9871, T10004
Differential Revision: https://secure.phabricator.com/D14814