2d1870cf7d
Summary: This change makes it possible to remove preferences. I also added a `Delete` context menu option to `DataInspector` because I needed it to implement this feature. passy confirmed that it makes sense to add this because delete is a common action. Fixes https://github.com/facebook/flipper/issues/451 Pull Request resolved: https://github.com/facebook/flipper/pull/1018 Reviewed By: jknoxville Differential Revision: D21086308 Pulled By: passy fbshipit-source-id: 551ff0908d5e6c93f58d6012b42e1ee3531de997