* Refactor PermissionsToggleController to not require a setting
* Update nativeMessaging to be optional on Chrome
* Update parsing.enableMecabParser setting to request permissions
* Update permissions page to use PermissionsToggleController
* Update permissions documentation
* Disable toggle for permissions which are not optional
* Improve styles for #content-scroll-focus
* Create new class to manage and control document focus
* Use new focus class
* Add a check to prevent redundant .blur calls