Add #defines for two new pseudo encodings:
 * cursor with alpha channel.
 * extended desktop resize.

https://github.com/rfbproto/rfbproto/blob/master/rfbproto.rst#pseudo-encodings



Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-id: 20201208115737.18581-6-kraxel@redhat.com