add ultra key

Signed-off-by: Mattias Andrée <maandree@operamail.com>
add protocol for announcing new keyboards and removal of keyboards

Signed-off-by: Mattias Andrée <maandree@operamail.com>
mds-kkbd: announce new keyboard when starting

Signed-off-by: Mattias Andrée <maandree@operamail.com>
keycodes not be larger than 2¹⁴

Signed-off-by: Mattias Andrée <maandree@operamail.com>
limit lvl*

Signed-off-by: Mattias Andrée <maandree@operamail.com>