Settings: Add keyboard features (2/2)

     * It adds:

        - CM's Ime switcher notification
        - Slim's fullscreen disable on landscape
        - Slim's force autorotation on IME
        - Cm's volume button control for navigate in the message
        - Slim's force to show always enter key

        Some fixes to the 4.2/4.3 implementations + added full multiuser support for all these features.