TryClientEvents already did this; this commit just moves the assignment
one level down so that no event source has to worry about sequence
numbers.
...No event source, that is, except XKB, which inexplicably calls
WriteToClient directly for several events.
Signed-off-by: Jamey Sharp <jamey@minilop.net>
Reviewed-by: Julien Cristau <jcristau@debian.org>
Reviewed-by: Adam Jackson <ajax@redhat.com>