The code processing incoming & sending outgoing messages from/to
clients used embedded magic numbers for all message IDs. This
made the code a little hard to follow. Add constants in the vnc.h
header file for all message IDs and use them in the code
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>