Implementation of Linux's DeviceKeyboardHandler.

[Animeshz]

Only X11 based linux distro is supported right now, if the X11 is not accessible (though should be in most GUI distros), we can safely fallback to read events from the /dev/uinput or /dev/input/eventX.

This operation is only granted when the root access is given, so we'll always prioritize the X11 way to handle the communication.

To be fixed: DeviceKeyboardHandler.