Update to latest API

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Add the xorg keycode offset to the key events

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Init with default XKB options

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Clarify a comment

Whatever xf86AddEnabledDevice does to the fd, it doesn't work with an
epollfd. Should probably investigate that further.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Keep track of the enabled devices

All libinput devices share the same file descriptor so make sure we don't
remove from the server's select loop until the last device is disabled.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Adjust for new API - current-screen-dimensions callback was removed

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>